Method and apparatus for receiving ppdu in wireless lan system

ABSTRACT

Proposed are a method and an apparatus for receiving a PPDU in a wireless LAN system. Specifically, a receiving STA receives a PPDU from a transmitting STA via broadband communication and decodes the PPDU. The PPDU is received on the basis of an OFDMA scheme. The PPDU includes a first signal field. The first signal field includes first information on a preamble puncturing pattern for each 80 MHz band in the broadband communication. The first information consists of a 4-bit bitmap for the 80 MHz band.

TECHNICAL FIELD

The present disclosure relates to a technique for receiving a PPDU in a WLAN system, and more particularly, to a method and apparatus for indicating a preamble puncturing pattern for each 80 MHz band in OFDMA transmission.

RELATED ART

A wireless local area network (WLAN) has been enhanced in various ways. For example, the IEEE 802.11ax standard has proposed an enhanced communication environment by using orthogonal frequency division multiple access (OFDMA) and downlink multi-user multiple input multiple output (DL MU MIMO) schemes.

The present specification proposes a technical feature that can be utilized in a new communication standard. For example, the new communication standard may be an extreme high throughput (EHT) standard which is currently being discussed. The EHT standard may use an increased bandwidth, an enhanced PHY layer protocol data unit (PPDU) structure, an enhanced sequence, a hybrid automatic repeat request (HARQ) scheme, or the like, which is newly proposed. The EHT standard may be referred to as the IEEE 802.11 be standard.

An increased number of spatial streams may be used in the new wireless LAN standard. In this case, in order to properly use the increased number of spatial streams, a signaling technique in the WLAN system may need to be improved.

SUMMARY Technical Objectives

The present disclosure proposes a method and apparatus for receiving a PPDU in a WLAN system.

Technical Solutions

An example of the present specification proposes a method for receiving a PPDU.

This embodiment may be performed in a network environment in which a next-generation wireless LAN system (e.g., IEEE 802.11 be or EHT wireless LAN system) is supported. The next-generation wireless LAN system is a wireless LAN system improved from the 802.11 ax system, and may satisfy backward compatibility with the 802.11 ax system.

This embodiment proposes a method and apparatus for indicating a preamble puncturing pattern of a broadband in OFDMA PPDU transmission.

A receiving station (STA) receives a Physical Protocol Data Unit (PPDU) through a broadband from a transmitting STA. The PPDU is received based on an Orthogonal Frequency Division Multiple Access (OFDMA) scheme.

The receiving STA decode the PPDU.

The PPDU includes a first signal field. The first signal field includes first information on a preamble puncturing pattern for each 80 MHz band in the broadband. The first information is set as a 4-bit bitmap for the each 80 MHz band. For example, when the broadband consists of three 80 MHz bands, the first information may be set as a 4-bit bitmap for the first 80 MHz band, a 4-bit bitmap for the second 80 MHz band, and/or a 4-bit bitmap for the third 80 MHz band.

The first signal field is a Universal-Signal (U-SIG) field. That is, this embodiment proposes a method of indicating (or signaling) a preamble puncturing pattern for each 80 MHz band based on a bitmap in the U-SIG field during OFDMA PPDU transmission. The U-SIG field may indicate a preamble puncturing pattern for each 80 MHz band for each 80 MHz band. Accordingly, information on the preamble puncturing pattern included in the U-SIG field may vary for each 80 MHz band.

Technical Effects

According to the embodiment proposed in this specification, during OFDMA PPDU transmission, the preamble puncturing pattern for the 80 MHz band of various STAs is checked and the STAs that do not participate in the corresponding PPDU transmission can transmit through the punctured channel. There is a new effect of increasing transmission efficiency and throughput.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an example of a transmitting apparatus and/or receiving apparatus of the present specification.

FIG. 2 is a conceptual view illustrating the structure of a wireless local area network (WLAN).

FIG. 3 illustrates a general link setup process.

FIG. 4 illustrates an example of a PPDU used in an IEEE standard.

FIG. 5 illustrates a layout of resource units (RUs) used in a band of 20 MHz.

FIG. 6 illustrates a layout of RUs used in a band of 40 MHz.

FIG. 7 illustrates a layout of RUs used in a band of 80 MHz.

FIG. 8 illustrates a structure of an HE-SIG-B field.

FIG. 9 illustrates an example in which a plurality of user STAs are allocated to the same RU through an MU-MIMO scheme.

FIG. 10 illustrates an operation based on UL-MU.

FIG. 11 illustrates an example of a trigger frame.

FIG. 12 illustrates an example of a common information field of a trigger frame.

FIG. 13 illustrates an example of a subfield included in a per user information field.

FIG. 14 describes a technical feature of the UORA scheme.

FIG. 15 illustrates an example of a channel used/supported/defined within a 2.4 GHz band.

FIG. 16 illustrates an example of a channel used/supported/defined within a 5 GHz band.

FIG. 17 illustrates an example of a channel used/supported/defined within a 6 GHz band.

FIG. 18 illustrates an example of a PPDU used in the present specification.

FIG. 19 illustrates an example of a modified transmission device and/or receiving apparatus/device of the present specification.

FIG. 20 shows an example of a PHY transmission procedure for HE SU PPDU.

FIG. 21 shows an example of a block diagram of a transmitting device for generating each field of an HE PPDU.

FIG. 22 shows an example of an EHT PPDU format.

FIG. 23 shows an example of a U-SIG format.

FIG. 24 shows an example of a 320 MHz channel configuration.

FIG. 25 shows another example of a 320 MHz channel configuration.

FIG. 26 is a flowchart illustrating the operation of the transmitting apparatus according to the present embodiment.

FIG. 27 is a flowchart illustrating the operation of the receiving apparatus according to the present embodiment.

FIG. 28 is a flowchart illustrating a procedure in which a transmitting STA transmits a PPDU according to the present embodiment.

FIG. 29 is a flowchart illustrating a procedure for a receiving STA to receive a PPDU according to the present embodiment.

DETAILED DESCRIPTION

In the present specification, “A or B” may mean “only A”, “only B” or “both A and B”. In other words, in the present specification, “A or B” may be interpreted as “A and/or B”. For example, in the present specification, “A, B, or C” may mean “only A”, “only B”, “only C”, or “any combination of A, B, C”.

A slash (/) or comma used in the present specification may mean “and/or”. For example, “A/B” may mean “A and/or B”. Accordingly, “A/B” may mean “only A”, “only B”, or “both A and B”. For example, “A, B, C” may mean “A, B, or C”.

In the present specification, “at least one of A and B” may mean “only A”, “only B”, or “both A and B”. In addition, in the present specification, the expression “at least one of A or B” or “at least one of A and/or B” may be interpreted as “at least one of A and B”.

In addition, in the present specification, “at least one of A, B, and C” may mean “only A”, “only B”, “only C”, or “any combination of A, B, and C”. In addition, “at least one of A, B, or C” or “at least one of A, B, and/or C” may mean “at least one of A, B, and C”.

In addition, a parenthesis used in the present specification may mean “for example”. Specifically, when indicated as “control information (EHT-signal)”, it may denote that “EHT-signal” is proposed as an example of the “control information”. In other words, the “control information” of the present specification is not limited to “EHT-signal”, and “EHT-signal” may be proposed as an example of the “control information”. In addition, when indicated as “control information (i.e., EHT-signal)”, it may also mean that “EHT-signal” is proposed as an example of the “control information”.

Technical features described individually in one figure in the present specification may be individually implemented, or may be simultaneously implemented.

The following example of the present specification may be applied to various wireless communication systems. For example, the following example of the present specification may be applied to a wireless local area network (WLAN) system. For example, the present specification may be applied to the IEEE 802.11 a/g/n/ac standard or the IEEE 802.11 ax standard. In addition, the present specification may also be applied to the newly proposed EHT standard or IEEE 802.11 be standard. In addition, the example of the present specification may also be applied to a new WLAN standard enhanced from the EHT standard or the IEEE 802.1 The standard. In addition, the example of the present specification may be applied to a mobile communication system. For example, it may be applied to a mobile communication system based on long term evolution (LTE) depending on a 3^(rd) generation partnership project (3GPP) standard and based on evolution of the LTE. In addition, the example of the present specification may be applied to a communication system of a 5G NR standard based on the 3GPP standard.

Hereinafter, in order to describe a technical feature of the present specification, a technical feature applicable to the present specification will be described.

FIG. 1 shows an example of a transmitting apparatus and/or receiving apparatus of the present specification.

In the example of FIG. 1 , various technical features described below may be performed. FIG. 1 relates to at least one station (STA). For example, STAs 110 and 120 of the present specification may also be called in various terms such as a mobile terminal, a wireless device, a wireless transmit/receive unit (WTRU), a user equipment (UE), a mobile station (MS), a mobile subscriber unit, or simply a user. The STAs 110 and 120 of the present specification may also be called in various terms such as a network, a base station, a node-B, an access point (AP), a repeater, a router, a relay, or the like. The STAs 110 and 120 of the present specification may also be referred to as various names such as a receiving apparatus, a transmitting apparatus, a receiving STA, a transmitting STA, a receiving device, a transmitting device, or the like.

For example, the STAs 110 and 120 may serve as an AP or a non-AP. That is, the STAs 110 and 120 of the present specification may serve as the AP and/or the non-AP.

The STAs 110 and 120 of the present specification may support various communication standards together in addition to the IEEE 802.11 standard. For example, a communication standard (e.g., LTE, LTE-A, 5G NR standard) or the like based on the 3 GPP standard may be supported. In addition, the STA of the present specification may be implemented as various devices such as a mobile phone, a vehicle, a personal computer, or the like. In addition, the STA of the present specification may support communication for various communication services such as voice calls, video calls, data communication, and self-driving (autonomous-driving), or the like.

The STAs 110 and 120 of the present specification may include a medium access control (MAC) conforming to the IEEE 802.11 standard and a physical layer interface for a radio medium.

The STAs 110 and 120 will be described below with reference to a sub-figure (a) of FIG. 1 .

The first STA 110 may include a processor 111, a memory 112, and a transceiver 113. The illustrated process, memory, and transceiver may be implemented individually as separate chips, or at least two blocks/functions may be implemented through a single chip.

The transceiver 113 of the first STA performs a signal transmission/reception operation. Specifically, an IEEE 802.11 packet (e.g., IEEE 802.11 a/b/g/n/ac/ax/be, etc.) may be transmitted/received.

For example, the first STA 110 may perform an operation intended by an AP. For example, the processor 111 of the AP may receive a signal through the transceiver 113, process a reception (RX) signal, generate a transmission (TX) signal, and provide control for signal transmission. The memory 112 of the AP may store a signal (e.g., RX signal) received through the transceiver 113, and may store a signal (e.g., TX signal) to be transmitted through the transceiver.

For example, the second STA 120 may perform an operation intended by a non-AP STA. For example, a transceiver 123 of a non-AP performs a signal transmission/reception operation. Specifically, an IEEE 802.11 packet (e.g., IEEE 802.11 a/b/g/n/ac/ax/be packet, etc.) may be transmitted/received.

For example, a processor 121 of the non-AP STA may receive a signal through the transceiver 123, process an RX signal, generate a TX signal, and provide control for signal transmission. A memory 122 of the non-AP STA may store a signal (e.g., RX signal) received through the transceiver 123, and may store a signal (e.g., TX signal) to be transmitted through the transceiver.

For example, an operation of a device indicated as an AP in the specification described below may be performed in the first STA 110 or the second STA 120. For example, if the first STA 110 is the AP, the operation of the device indicated as the AP may be controlled by the processor 111 of the first STA 110, and a related signal may be transmitted or received through the transceiver 113 controlled by the processor 111 of the first STA 110. In addition, control information related to the operation of the AP or a TX/RX signal of the AP may be stored in the memory 112 of the first STA 110. In addition, if the second STA 120 is the AP, the operation of the device indicated as the AP may be controlled by the processor 121 of the second STA 120, and a related signal may be transmitted or received through the transceiver 123 controlled by the processor 121 of the second STA 120. In addition, control information related to the operation of the AP or a TX/RX signal of the AP may be stored in the memory 122 of the second STA 120.

For example, in the specification described below, an operation of a device indicated as a non-AP (or user-STA) may be performed in the first STA 110 or the second STA 120. For example, if the second STA 120 is the non-AP, the operation of the device indicated as the non-AP may be controlled by the processor 121 of the second STA 120, and a related signal may be transmitted or received through the transceiver 123 controlled by the processor 121 of the second STA 120. In addition, control information related to the operation of the non-AP or a TX/RX signal of the non-AP may be stored in the memory 122 of the second STA 120. For example, if the first STA 110 is the non-AP, the operation of the device indicated as the non-AP may be controlled by the processor 111 of the first STA 110, and a related signal may be transmitted or received through the transceiver 113 controlled by the processor 111 of the first STA 110. In addition, control information related to the operation of the non-AP or a TX/RX signal of the non-AP may be stored in the memory 112 of the first STA 110.

In the specification described below, a device called a (transmitting/receiving) STA, a first STA, a second STA, a STA1, a STA2, an AP, a first AP, a second AP, an AP1, an AP2, a (transmitting/receiving) terminal, a (transmitting/receiving) device, a (transmitting/receiving) apparatus, a network, or the like may imply the STAs 110 and 120 of FIG. 1 . For example, a device indicated as, without a specific reference numeral, the (transmitting/receiving) STA, the first STA, the second STA, the STA1, the STA2, the AP, the first AP, the second AP, the AP1, the AP2, the (transmitting/receiving) terminal, the (transmitting/receiving) device, the (transmitting/receiving) apparatus, the network, or the like may imply the STAs 110 and 120 of FIG. 1 . For example, in the following example, an operation in which various STAs transmit/receive a signal (e.g., a PPDU) may be performed in the transceivers 113 and 123 of FIG. 1 . In addition, in the following example, an operation in which various STAs generate a TX/RX signal or perform data processing and computation in advance for the TX/RX signal may be performed in the processors 111 and 121 of FIG. 1 . For example, an example of an operation for generating the TX/RX signal or performing the data processing and computation in advance may include: 1) an operation of determining/obtaining/configuring/computing/decoding/encoding bit information of a sub-field (SIG, STF, LTF, Data) included in a PPDU; 2) an operation of determining/configuring/obtaining a time resource or frequency resource (e.g., a subcarrier resource) or the like used for the sub-field (SIG, STF, LTF, Data) included the PPDU; 3) an operation of determining/configuring/obtaining a specific sequence (e.g., a pilot sequence, an STF/LTF sequence, an extra sequence applied to SIG) or the like used for the sub-field (SIG, STF, LTF, Data) field included in the PPDU; 4) a power control operation and/or power saving operation applied for the STA; and 5) an operation related to determining/obtaining/configuring/decoding/encoding or the like of an ACK signal. In addition, in the following example, a variety of information used by various STAs for determining/obtaining/configuring/computing/decoding/decoding a TX/RX signal (e.g., information related to a field/subfield/control field/parameter/power or the like) may be stored in the memories 112 and 122 of FIG. 1 .

The aforementioned device/STA of the sub-FIG. (a) of FIG. 1 may be modified as shown in the sub-FIG. (b) of FIG. 1 . Hereinafter, the STAs 110 and 120 of the present specification will be described based on the sub-FIG. (b) of FIG. 1 .

For example, the transceivers 113 and 123 illustrated in the sub-FIG. (b) of FIG. 1 may perform the same function as the aforementioned transceiver illustrated in the sub-FIG. (a) of FIG. 1 . For example, processing chips 114 and 124 illustrated in the sub-FIG. (b) of FIG. 1 may include the processors 111 and 121 and the memories 112 and 122. The processors 111 and 121 and memories 112 and 122 illustrated in the sub-FIG. (b) of FIG. 1 may perform the same function as the aforementioned processors 111 and 121 and memories 112 and 122 illustrated in the sub-FIG. (a) of FIG. 1 .

A mobile terminal, a wireless device, a wireless transmit/receive unit (WTRU), a user equipment (UE), a mobile station (MS), a mobile subscriber unit, a user, a user STA, a network, a base station, a Node-B, an access point (AP), a repeater, a router, a relay, a receiving unit, a transmitting unit, a receiving STA, a transmitting STA, a receiving device, a transmitting device, a receiving apparatus, and/or a transmitting apparatus, which are described below, may imply the STAs 110 and 120 illustrated in the sub-FIGS. (a)/(b) of FIG. 1 , or may imply the processing chips 114 and 124 illustrated in the sub-FIG. (b) of FIG. 1 . That is, a technical feature of the present specification may be performed in the STAs 110 and 120 illustrated in the sub-FIGS. (a)/(b) of FIG. 1 , or may be performed only in the processing chips 114 and 124 illustrated in the sub-FIG. (b) of FIG. 1 . For example, a technical feature in which the transmitting STA transmits a control signal may be understood as a technical feature in which a control signal generated in the processors 111 and 121 illustrated in the sub-FIGS. (a)/(b) of FIG. 1 is transmitted through the transceivers 113 and 123 illustrated in the sub-FIGS. (a)/(b) of FIG. 1 . Alternatively, the technical feature in which the transmitting STA transmits the control signal may be understood as a technical feature in which the control signal to be transferred to the transceivers 113 and 123 is generated in the processing chips 114 and 124 illustrated in the sub-FIG. (b) of FIG. 1 .

For example, a technical feature in which the receiving STA receives the control signal may be understood as a technical feature in which the control signal is received by means of the transceivers 113 and 123 illustrated in the sub-FIG. (a) of FIG. 1 . Alternatively, the technical feature in which the receiving STA receives the control signal may be understood as the technical feature in which the control signal received in the transceivers 113 and 123 illustrated in the sub-FIG. (a) of FIG. 1 is obtained by the processors 111 and 121 illustrated in the sub-FIG. (a) of FIG. 1 . Alternatively, the technical feature in which the receiving STA receives the control signal may be understood as the technical feature in which the control signal received in the transceivers 113 and 123 illustrated in the sub-FIG. (b) of FIG. 1 is obtained by the processing chips 114 and 124 illustrated in the sub-FIG. (b) of FIG. 1 .

Referring to the sub-FIG. (b) of FIG. 1 , software codes 115 and 125 may be included in the memories 112 and 122. The software codes 115 and 126 may include instructions for controlling an operation of the processors 111 and 121. The software codes 115 and 125 may be included as various programming languages.

The processors 111 and 121 or processing chips 114 and 124 of FIG. 1 may include an application-specific integrated circuit (ASIC), other chipsets, a logic circuit and/or a data processing device. The processor may be an application processor (AP). For example, the processors 111 and 121 or processing chips 114 and 124 of FIG. 1 may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), and a modulator and demodulator (modem). For example, the processors 111 and 121 or processing chips 114 and 124 of FIG. 1 may be SNAPDRAGONTM series of processors made by Qualcomm®, EXYNOSTM series of processors made by Samsung®, A series of processors made by Apple®, HELIOTM series of processors made by MediaTek®, ATOMTM series of processors made by Intel® or processors enhanced from these processors.

In the present specification, an uplink may imply a link for communication from a non-AP STA to an SP STA, and an uplink PPDU/packet/signal or the like may be transmitted through the uplink. In addition, in the present specification, a downlink may imply a link for communication from the AP STA to the non-AP STA, and a downlink PPDU/packet/signal or the like may be transmitted through the downlink.

FIG. 2 is a conceptual view illustrating the structure of a wireless local area network (WLAN).

An upper part of FIG. 2 illustrates the structure of an infrastructure basic service set (BSS) of institute of electrical and electronic engineers (IEEE) 802.11.

Referring the upper part of FIG. 2 , the wireless LAN system may include one or more infrastructure BSSs 200 and 205 (hereinafter, referred to as BSS). The BSSs 200 and 205 as a set of an AP and a STA such as an access point (AP) 225 and a station (STA1) 200-1 which are successfully synchronized to communicate with each other are not concepts indicating a specific region. The BSS 205 may include one or more STAs 205-1 and 205-2 which may be joined to one AP 230.

The BSS may include at least one STA, APs providing a distribution service, and a distribution system (DS) 210 connecting multiple APs.

The distribution system 210 may implement an extended service set (ESS) 240 extended by connecting the multiple BSSs 200 and 205. The ESS 240 may be used as a term indicating one network configured by connecting one or more APs 225 or 230 through the distribution system 210. The AP included in one ESS 240 may have the same service set identification (SSID).

A portal 220 may serve as a bridge which connects the wireless LAN network (IEEE 802.11) and another network (e.g., 802.X).

In the BSS illustrated in the upper part of FIG. 2 , a network between the APs 225 and 230 and a network between the APs 225 and 230 and the STAs 200-1, 205-1, and 205-2 may be implemented. However, the network is configured even between the STAs without the APs 225 and 230 to perform communication. A network in which the communication is performed by configuring the network even between the STAs without the APs 225 and 230 is defined as an Ad-Hoc network or an independent basic service set (IBSS).

A lower part of FIG. 2 illustrates a conceptual view illustrating the IBSS.

Referring to the lower part of FIG. 2 , the IBSS is a BSS that operates in an Ad-Hoc mode. Since the IBSS does not include the access point (AP), a centralized management entity that performs a management function at the center does not exist. That is, in the IBSS, STAs 250-1, 250-2, 250-3, 255-4, and 255-5 are managed by a distributed manner. In the IBSS, all STAs 250-1, 250-2, 250-3, 255-4, and 255-5 may be constituted by movable STAs and are not permitted to access the DS to constitute a self-contained network.

FIG. 3 illustrates a general link setup process.

In S310, a STA may perform a network discovery operation. The network discovery operation may include a scanning operation of the STA. That is, to access a network, the STA needs to discover a participating network. The STA needs to identify a compatible network before participating in a wireless network, and a process of identifying a network present in a particular area is referred to as scanning. Scanning methods include active scanning and passive scanning.

FIG. 3 illustrates a network discovery operation including an active scanning process. In active scanning, a STA performing scanning transmits a probe request frame and waits for a response to the probe request frame in order to identify which AP is present around while moving to channels. A responder transmits a probe response frame as a response to the probe request frame to the STA having transmitted the probe request frame. Here, the responder may be a STA that transmits the last beacon frame in a BSS of a channel being scanned. In the BSS, since an AP transmits a beacon frame, the AP is the responder. In an IBSS, since STAs in the IBSS transmit a beacon frame in turns, the responder is not fixed. For example, when the STA transmits a probe request frame via channel 1 and receives a probe response frame via channel 1, the STA may store BSS-related information included in the received probe response frame, may move to the next channel (e.g., channel 2), and may perform scanning (e.g., transmits a probe request and receives a probe response via channel 2) by the same method.

Although not shown in FIG. 3 , scanning may be performed by a passive scanning method. In passive scanning, a STA performing scanning may wait for a beacon frame while moving to channels. A beacon frame is one of management frames in IEEE 802.11 and is periodically transmitted to indicate the presence of a wireless network and to enable the STA performing scanning to find the wireless network and to participate in the wireless network. In a BSS, an AP serves to periodically transmit a beacon frame. In an IBSS, STAs in the IBSS transmit a beacon frame in turns. Upon receiving the beacon frame, the STA performing scanning stores information related to a BSS included in the beacon frame and records beacon frame information in each channel while moving to another channel. The STA having received the beacon frame may store BSS-related information included in the received beacon frame, may move to the next channel, and may perform scanning in the next channel by the same method.

After discovering the network, the STA may perform an authentication process in S320. The authentication process may be referred to as a first authentication process to be clearly distinguished from the following security setup operation in S340. The authentication process in S320 may include a process in which the STA transmits an authentication request frame to the AP and the AP transmits an authentication response frame to the STA in response. The authentication frames used for an authentication request/response are management frames.

The authentication frames may include information related to an authentication algorithm number, an authentication transaction sequence number, a status code, a challenge text, a robust security network (RSN), and a finite cyclic group.

The STA may transmit the authentication request frame to the AP. The AP may determine whether to allow the authentication of the STA based on the information included in the received authentication request frame. The AP may provide the authentication processing result to the STA via the authentication response frame.

When the STA is successfully authenticated, the STA may perform an association process in S330. The association process includes a process in which the STA transmits an association request frame to the AP and the AP transmits an association response frame to the STA in response. The association request frame may include, for example, information related to various capabilities, a beacon listen interval, a service set identifier (SSID), a supported rate, a supported channel, RSN, a mobility domain, a supported operating class, a traffic indication map (TIM) broadcast request, and an interworking service capability. The association response frame may include, for example, information related to various capabilities, a status code, an association ID (AID), a supported rate, an enhanced distributed channel access (EDCA) parameter set, a received channel power indicator (RCPI), a received signal-to-noise indicator (RSNI), a mobility domain, a timeout interval (association comeback time), an overlapping BSS scanning parameter, a TIM broadcast response, and a QoS map.

In S340, the STA may perform a security setup process. The security setup process in S340 may include a process of setting up a private key through four-way handshaking, for example, through an extensible authentication protocol over LAN (EAPOL) frame.

FIG. 4 illustrates an example of a PPDU used in an IEEE standard.

As illustrated, various types of PHY protocol data units (PPDUs) are used in IEEE a/g/n/ac standards. Specifically, an LTF and a STF include a training signal, a SIG-A and a SIG-B include control information for a receiving STA, and a data field includes user data corresponding to a PSDU (MAC PDU/aggregated MAC PDU).

FIG. 4 also includes an example of an HE PPDU according to IEEE 802.11ax. The HE PPDU according to FIG. 4 is an illustrative PPDU for multiple users. An HE-SIG-B may be included only in a PPDU for multiple users, and an HE-SIG-B may be omitted in a PPDU for a single user.

As illustrated in FIG. 4 , the HE-PPDU for multiple users (MUs) may include a legacy-short training field (L-STF), a legacy-long training field (L-LTF), a legacy-signal (L-SIG), a high efficiency-signal A (HE-SIG A), a high efficiency-signal-B (HE-SIG B), a high efficiency-short training field (HE-STF), a high efficiency-long training field (HE-LTF), a data field (alternatively, an MAC payload), and a packet extension (PE) field. The respective fields may be transmitted for illustrated time periods (i.e., 4 or 8 µs).

Hereinafter, a resource unit (RU) used for a PPDU is described. An RU may include a plurality of subcarriers (or tones). An RU may be used to transmit a signal to a plurality of STAs according to OFDMA. Further, an RU may also be defined to transmit a signal to one STA. An RU may be used for an STF, an LTF, a data field, or the like.

FIG. 5 illustrates a layout of resource units (RUs) used in a band of 20 MHz.

As illustrated in FIG. 5 , resource units (RUs) corresponding to different numbers of tones (i.e., subcarriers) may be used to form some fields of an HE-PPDU. For example, resources may be allocated in illustrated RUs for an HE-STF, an HE-LTF, and a data field.

As illustrated in the uppermost part of FIG. 5 , a 26-unit (i.e., a unit corresponding to 26 tones) may be disposed. Six tones may be used for a guard band in the leftmost band of the 20 MHz band, and five tones may be used for a guard band in the rightmost band of the 20 MHz band. Further, seven DC tones may be inserted in a center band, that is, a DC band, and a 26-unit corresponding to 13 tones on each of the left and right sides of the DC band may be disposed. A 26-unit, a 52-unit, and a 106-unit may be allocated to other bands. Each unit may be allocated for a receiving STA, that is, a user.

The layout of the RUs in FIG. 5 may be used not only for a multiple users (MUs) but also for a single user (SU), in which case one 242-unit may be used and three DC tones may be inserted as illustrated in the lowermost part of FIG. 5 .

Although FIG. 5 proposes RUs having various sizes, that is, a 26-RU, a 52-RU, a 106-RU, and a 242-RU, specific sizes of RUs may be extended or increased. Therefore, the present embodiment is not limited to the specific size of each RU (i.e., the number of corresponding tones).

FIG. 6 illustrates a layout of RUs used in a band of 40 MHz.

Similarly to FIG. 5 in which RUs having various sizes are used, a 26-RU, a 52-RU, a 106-RU, a 242-RU, a 484-RU, and the like may be used in an example of FIG. 6 . Further, five DC tones may be inserted in a center frequency, 12 tones may be used for a guard band in the leftmost band of the 40 MHz band, and 11 tones may be used for a guard band in the rightmost band of the 40 MHz band.

As illustrated in FIG. 6 , when the layout of the RUs is used for a single user, a 484-RU may be used. The specific number of RUs may be changed similarly to FIG. 5 .

FIG. 7 illustrates a layout of RUs used in a band of 80 MHz.

Similarly to FIG. 5 and FIG. 6 in which RUs having various sizes are used, a 26-RU, a 52-RU, a 106-RU, a 242-RU, a 484-RU, a 996-RU, and the like may be used in an example of FIG. 7 . Further, seven DC tones may be inserted in the center frequency, 12 tones may be used for a guard band in the leftmost band of the 80 MHz band, and 11 tones may be used for a guard band in the rightmost band of the 80 MHz band. In addition, a 26-RU corresponding to 13 tones on each of the left and right sides of the DC band may be used.

As illustrated in FIG. 7 , when the layout of the RUs is used for a single user, a 996-RU may be used, in which case five DC tones may be inserted.

The RU described in the present specification may be used in uplink (UL) communication and downlink (DL) communication. For example, when UL-MU communication which is solicited by a trigger frame is performed, a transmitting STA (e.g., an AP) may allocate a first RU (e.g., 26/52/106/242-RU, etc.) to a first STA through the trigger frame, and may allocate a second RU (e.g., 26/52/106/242-RU, etc.) to a second STA. Thereafter, the first STA may transmit a first trigger-based PPDU based on the first RU, and the second STA may transmit a second trigger-based PPDU based on the second RU. The first/second trigger-based PPDU is transmitted to the AP at the same (or overlapped) time period.

For example, when a DL MU PPDU is configured, the transmitting STA (e.g., AP) may allocate the first RU (e.g., 26/52/106/242-RU. etc.) to the first STA, and may allocate the second RU (e.g., 26/52/106/242-RU, etc.) to the second STA. That is, the transmitting STA (e.g., AP) may transmit HE-STF, HE-LTF, and Data fields for the first STA through the first RU in one MU PPDU, and may transmit HE-STF, HE-LTF, and Data fields for the second STA through the second RU.

Information related to a layout of the RU may be signaled through HE-SIG-B.

FIG. 8 illustrates a structure of an HE-SIG-B field.

As illustrated, an HE-SIG-B field 810 includes a common field 820 and a user-specific field 830. The common field 820 may include information commonly applied to all users (i.e., user STAs) which receive SIG-B. The user-specific field 830 may be called a user-specific control field. When the SIG-B is transferred to a plurality of users, the user-specific field 830 may be applied only any one of the plurality of users.

As illustrated in FIG. 8 , the common field 820 and the user-specific field 830 may be separately encoded.

The common field 820 may include RU allocation information of N*8 bits. For example, the RU allocation information may include information related to a location of an RU. For example, when a 20 MHz channel is used as shown in FIG. 5 , the RU allocation information may include information related to a specific frequency band to which a specific RU (26-RU/52-RU/106-RU) is arranged.

An example of a case in which the RU allocation information consists of 8 bits is as follows.

TABLE 1 8 bits indices (B7 B6 B5 B4 B3 B2 B1 B0) #1 #2 #3 #4 #5 #6 #7 #8 #9 Number of entries 00000000 26 26 26 26 26 26 26 26 26 1 00000001 26 26 26 26 26 26 26 52 1 00000010 26 26 26 26 26 52 26 26 1 00000011 26 26 26 26 26 52 52 1 00000100 26 26 52 26 26 26 26 26 1 00000101 26 26 52 26 26 26 52 1 00000110 26 26 52 26 52 26 26 1 00000111 26 26 52 26 52 52 1 00001000 52 26 26 26 26 26 26 26 1

As shown the example of FIG. 5 , up to nine 26-RUs may be allocated to the 20 MHz channel. When the RU allocation information of the common field 820 is set to “00000000” as shown in Table 1, the nine 26-RUs may be allocated to a corresponding channel (i.e., 20 MHz). In addition, when the RU allocation information of the common field 820 is set to “00000001” as shown in Table 1, seven 26-RUs and one 52-RU are arranged in a corresponding channel. That is, in the example of FIG. 5 , the 52-RU may be allocated to the rightmost side, and the seven 26-RUs may be allocated to the left thereof.

The example of Table 1 shows only some of RU locations capable of displaying the RU allocation information.

For example, the RU allocation information may include an example of Table 2 below.

TABLE 2 8 bits indices (B7 B6 B5 B4 B3 B2 B1 B0) #1 #2 #3 #4 #5 #6 #7 #8 #9 Number of entries 01000y₂y₁y₀ 106 26 26 26 26 26 8 01001y₂y₁y₀ 106 26 26 26 52 8

“01000y2y1y0” relates to an example in which a 106-RU is allocated to the leftmost side of the 20 MHz channel, and five 26-RUs are allocated to the right side thereof. In this case, a plurality of STAs (e.g., user-STAs) may be allocated to the 106-RU, based on an MU-MIMO scheme. Specifically, up to 8 STAs (e.g., user-STAs) may be allocated to the 106-RU, and the number of STAs (e.g., user-STAs) allocated to the 106-RU is determined based on 3-bit information (y2yly0). For example, when the 3-bit information (y2yly0) is set to N, the number of STAs (e.g., user-STAs) allocated to the 106-RU based on the MU-MIMO scheme may be N+1.

In general, a plurality of STAs (e.g., user STAs) different from each other may be allocated to a plurality of RUs. However, the plurality of STAs (e.g., user STAs) may be allocated to one or more RUs having at least a specific size (e.g., 106 subcarriers), based on the MU-MIMO scheme.

As shown in FIG. 8 , the user-specific field 830 may include a plurality of user fields. As described above, the number of STAs (e.g., user STAs) allocated to a specific channel may be determined based on the RU allocation information of the common field 820. For example, when the RU allocation information of the common field 820 is “00000000”, one user STA may be allocated to each of nine 26-RUs (e.g., nine user STAs may be allocated). That is, up to 9 user STAs may be allocated to a specific channel through an OFDMA scheme. In other words, up to 9 user STAs may be allocated to a specific channel through a non-MU-MIMO scheme.

For example, when RU allocation is set to “01000y2y1y0”, a plurality of STAs may be allocated to the 106-RU arranged at the leftmost side through the MU-MIMO scheme, and five user STAs may be allocated to five 26-RUs arranged to the right side thereof through the non-MU MIMO scheme. This case is specified through an example of FIG. 9 .

FIG. 9 illustrates an example in which a plurality of user STAs are allocated to the same RU through an MU-MIMO scheme.

For example, when RU allocation is set to “01000010” as shown in FIG. 9 , a 106-RU may be allocated to the leftmost side of a specific channel, and five 26-RUs may be allocated to the right side thereof. In addition, three user STAs may be allocated to the 106-RU through the MU-MIMO scheme. As a result, since eight user STAs are allocated, the user-specific field 830 of HE-SIG-B may include eight user fields.

The eight user fields may be expressed in the order shown in FIG. 9 . In addition, as shown in FIG. 8 , two user fields may be implemented with one user block field.

The user fields shown in FIG. 8 and FIG. 9 may be configured based on two formats. That is, a user field related to an MU-MIMO scheme may be configured in a first format, and a user field related to a non-MIMO scheme may be configured in a second format. Referring to the example of FIG. 9 , a user field 1 to a user field 3 may be based on the first format, and a user field 4 to a user field 8 may be based on the second format. The first format or the second format may include bit information of the same length (e.g., 21 bits).

Each user field may have the same size (e.g., 21 bits). For example, the user field of the first format (the first of the MU-MIMO scheme) may be configured as follows.

For example, a first bit (i.e., B0-B10) in the user field (i.e., 21 bits) may include identification information (e.g., STA-ID, partial AID, etc.) of a user STA to which a corresponding user field is allocated. In addition, a second bit (i.e., B11-B14) in the user field (i.e., 21 bits) may include information related to a spatial configuration. Specifically, an example of the second bit (i.e., B11-B14) may be as shown in Table 3 and Table 4 below.

TABLE 3 N_(user) B3...B0 N_(STS) [1] N_(STS) [2] N_(STS) [3] N_(STS) [4] N_(STS) [5] N_(STS) [6] N_(STS) [7] N_(STS) 191 Total N_(STS) Number of entries 2 0000-0011 1-4 1 2-5 10 0100-0110 2-4 2 4-6 0111-1000 3-4 3 6-7 1001 4 4 8 3 0000-0011 1-4 1 1 3-6 13 0100-0110 2-4 2 1 5-7 0111-1000 3-4 3 1 7-8 1001-1011 2-4 2 2 6-8 1100 3 3 2 8 4 0000-0011 1-4 1 1 1 4-7 11 0100-0110 2-4 2 1 1 6-8 0111 3 3 1 1 8 1000-1001 2-3 2 2 1 7-8 1010 2 2 2 2 8

TABLE 4 N_(user) B3...B6 N_(STS) [1] N_(STS) [2] N_(STS) [3] N_(STS) [4] N_(STS) [5] N_(STS) [6] N_(STS) [7] N_(STS) [8] Total N_(STS) Number of entries 5 0000-0011 1-4 1 1 1 3 5-8 7 0100-0101 2-3 2 1 1 1 7-8 0110 2 2 2 1 1 8 6 0000-0010 1-3 1 1 1 1 1 6-8 4 0011 2 2 1 1 1 1 8 7 0000-0001 1-2 1 1 1 1 1 1 7-8 2 8 0000 1 1 1 1 1 1 1 1 8 1

As shown in Table 3 and/or Table 4, the second bit (e.g., B11-B14) may include information related to the number of spatial streams allocated to the plurality of user STAs which are allocated based on the MU-MIMO scheme. For example, when three user STAs are allocated to the 106-RU based on the MU-MIMO scheme as shown in FIG. 9 , N_user is set to “3”. Therefore, values of N_STS[1], N_STS[2], and N_STS[3] may be determined as shown in Table 3. For example, when a value of the second bit (B11-B14) is “0011”, it may be set to N_STS[1]=4, N_STS[2]=1, N_STS[3]=1. That is, in the example of FIG. 9 , four spatial streams may be allocated to the user field 1, one spatial stream may be allocated to the user field 1, and one spatial stream may be allocated to the user field 3.

As shown in the example of Table 3 and/or Table 4, information (i.e., the second bit, B11-B14) related to the number of spatial streams for the user STA may consist of 4 bits. In addition, the information (i.e., the second bit, B11-B14) on the number of spatial streams for the user STA may support up to eight spatial streams. In addition, the information (i.e., the second bit, B11-B14) on the number of spatial streams for the user STA may support up to four spatial streams for one user STA.

In addition, a third bit (i.e., B15-18) in the user field (i.e., 21 bits) may include modulation and coding scheme (MCS) information. The MCS information may be applied to a data field in a PPDU including corresponding SIG-B.

An MCS, MCS information, an MCS index, an MCS field, or the like used in the present specification may be indicated by an index value. For example, the MCS information may be indicated by an index 0 to an index 11. The MCS information may include information related to a constellation modulation type (e.g., BPSK, QPSK, 16-QAM, 64-QAM, 256-QAM, 1024-QAM, etc.) and information related to a coding rate (e.g., ½, ⅔, ¾, 5/6e, etc.). Information related to a channel coding type (e.g., LCC or LDPC) may be excluded in the MCS information.

In addition, a fourth bit (i.e., B19) in the user field (i.e., 21 bits) may be a reserved field.

In addition, a fifth bit (i.e., B20) in the user field (i.e., 21 bits) may include information related to a coding type (e.g., BCC or LDPC). That is, the fifth bit (i.e., B20) may include information related to a type (e.g., BCC or LDPC) of channel coding applied to the data field in the PPDU including the corresponding SIG-B.

The aforementioned example relates to the user field of the first format (the format of the MU-MIMO scheme). An example of the user field of the second format (the format of the non-MU-MIMO scheme) is as follows.

A first bit (e.g., B0-B10) in the user field of the second format may include identification information of a user STA. In addition, a second bit (e.g., B11-B13) in the user field of the second format may include information related to the number of spatial streams applied to a corresponding RU. In addition, a third bit (e.g., B14) in the user field of the second format may include information related to whether a beamforming steering matrix is applied. A fourth bit (e.g., B15-B18) in the user field of the second format may include modulation and coding scheme (MCS) information. In addition, a fifth bit (e.g., B19) in the user field of the second format may include information related to whether dual carrier modulation (DCM) is applied. In addition, a sixth bit (i.e., B20) in the user field of the second format may include information related to a coding type (e.g., BCC or LDPC).

FIG. 10 illustrates an operation based on UL-MU. As illustrated, a transmitting STA (e.g., an AP) may perform channel access through contending (e.g., a backoff operation), and may transmit a trigger frame 1030. That is, the transmitting STA may transmit a PPDU including the trigger frame 1030. Upon receiving the PPDU including the trigger frame, a trigger-based (TB) PPDU is transmitted after a delay corresponding to SIFS.

TB PPDUs 1041 and 1042 may be transmitted at the same time period, and may be transmitted from a plurality of STAs (e.g., user STAs) having AIDs indicated in the trigger frame 1030. An ACK frame 1050 for the TB PPDU may be implemented in various forms.

A specific feature of the trigger frame is described with reference to FIG. 11 to FIG. 13 . Even if UL-MU communication is used, an orthogonal frequency division multiple access (OFDMA) scheme or an MU MIMO scheme may be used, and the OFDMA and MU-MIMO schemes may be simultaneously used.

FIG. 11 illustrates an example of a trigger frame. The trigger frame of FIG. 11 allocates a resource for uplink multiple-user (MU) transmission, and may be transmitted, for example, from an AP. The trigger frame may be configured of a MAC frame, and may be included in a PPDU.

Each field shown in FIG. 11 may be partially omitted, and another field may be added. In addition, a length of each field may be changed to be different from that shown in the figure.

A frame control field 1110 of FIG. 11 may include information related to a MAC protocol version and extra additional control information. A duration field 1120 may include time information for NAV configuration or information related to an identifier (e.g., AID) of a STA.

In addition, an RA field 1130 may include address information of a receiving STA of a corresponding trigger frame, and may be optionally omitted. A TA field 1140 may include address information of a STA (e.g., an AP) which transmits the corresponding trigger frame. A common information field 1150 includes common control information applied to the receiving STA which receives the corresponding trigger frame. For example, a field indicating a length of an L-SIG field of an uplink PPDU transmitted in response to the corresponding trigger frame or information for controlling content of a SIG-A field (i.e., HE-SIG-A field) of the uplink PPDU transmitted in response to the corresponding trigger frame may be included. In addition, as common control information, information related to a length of a CP of the uplink PPDU transmitted in response to the corresponding trigger frame or information related to a length of an LTF field may be included.

In addition, per user information fields 1160#1 to 1160#N corresponding to the number of receiving STAs which receive the trigger frame of FIG. 11 are preferably included. The per user information field may also be called an “allocation field”.

In addition, the trigger frame of FIG. 11 may include a padding field 1170 and a frame check sequence field 1180.

Each of the per user information fields 1160#1 to 1160#N shown in FIG. 11 may include a plurality of subfields.

FIG. 12 illustrates an example of a common information field of a trigger frame. A subfield of FIG. 12 may be partially omitted, and an extra subfield may be added. In addition, a length of each subfield illustrated may be changed.

A length field 1210 illustrated has the same value as a length field of an L-SIG field of an uplink PPDU transmitted in response to a corresponding trigger frame, and a length field of the L-SIG field of the uplink PPDU indicates a length of the uplink PPDU. As a result, the length field 1210 of the trigger frame may be used to indicate the length of the corresponding uplink PPDU.

In addition, a cascade identifier field 1220 indicates whether a cascade operation is performed. The cascade operation implies that downlink MU transmission and uplink MU transmission are performed together in the same TXOP. That is, it implies that downlink MU transmission is performed and thereafter uplink MU transmission is performed after a pre-set time (e.g., SIFS). During the cascade operation, only one transmitting device (e.g., AP) may perform downlink communication, and a plurality of transmitting devices (e.g., non-APs) may perform uplink communication.

A CS request field 1230 indicates whether a wireless medium state or a NAV or the like is necessarily considered in a situation where a receiving device which has received a corresponding trigger frame transmits a corresponding uplink PPDU.

An HE-SIG-A information field 1240 may include information for controlling content of a SIG-A field (i.e., HE-SIG-A field) of the uplink PPDU in response to the corresponding trigger frame.

A CP and LTF type field 1250 may include information related to a CP length and LTF length of the uplink PPDU transmitted in response to the corresponding trigger frame. A trigger type field 1260 may indicate a purpose of using the corresponding trigger frame, for example, typical triggering, triggering for beamforming, a request for block ACK/NACK, or the like.

It may be assumed that the trigger type field 1260 of the trigger frame in the present specification indicates a trigger frame of a basic type for typical triggering. For example, the trigger frame of the basic type may be referred to as a basic trigger frame.

FIG. 13 illustrates an example of a subfield included in a per user information field. A user information field 1300 of FIG. 13 may be understood as any one of the per user information fields 1160#1 to 1160#N mentioned above with reference to FIG. 11 . A subfield included in the user information field 1300 of FIG. 13 may be partially omitted, and an extra subfield may be added. In addition, a length of each subfield illustrated may be changed.

A user identifier field 1310 of FIG. 13 indicates an identifier of a STA (i.e., receiving STA) corresponding to per user information. An example of the identifier may be the entirety or part of an association identifier (AID) value of the receiving STA.

In addition, an RU allocation field 1320 may be included. That is, when the receiving STA identified through the user identifier field 1310 transmits a TB PPDU in response to the trigger frame, the TB PPDU is transmitted through an RU indicated by the RU allocation field 1320. In this case, the RU indicated by the RU allocation field 1320 may be an RU shown in FIG. 5 , FIG. 6 , and FIG. 7 .

The subfield of FIG. 13 may include a coding type field 1330. The coding type field 1330 may indicate a coding type of the TB PPDU. For example, when BCC coding is applied to the TB PPDU, the coding type field 1330 may be set to '1', and when LDPC coding is applied, the coding type field 1330 may be set to ‘0’.

In addition, the subfield of FIG. 13 may include an MCS field 1340. The MCS field 1340 may indicate an MCS scheme applied to the TB PPDU. For example, when BCC coding is applied to the TB PPDU, the coding type field 1330 may be set to '1', and when LDPC coding is applied, the coding type field 1330 may be set to '0'.

Hereinafter, a UL OFDMA-based random access (UORA) scheme will be described.

FIG. 14 describes a technical feature of the UORA scheme.

A transmitting STA (e.g., an AP) may allocate six RU resources through a trigger frame as shown in FIG. 14 . Specifically, the AP may allocate a 1st RU resource (AID 0, RU 1), a 2nd RU resource (AID 0, RU 2), a 3rd RU resource (AID 0, RU 3), a 4th RU resource (AID 2045, RU 4), a 5th RU resource (AID 2045, RU 5), and a 6th RU resource (AID 3, RU 6). Information related to the AID 0, AID 3, or AID 2045 may be included, for example, in the user identifier field 1310 of FIG. 13 . Information related to the RU 1 to RU 6 may be included, for example, in the RU allocation field 1320 of FIG. 13 . AID=0 may imply a UORA resource for an associated STA, and AID=2045 may imply a UORA resource for an un-associated STA. Accordingly, the 1st to 3rd RU resources of FIG. 14 may be used as a UORA resource for the associated STA, the 4th and 5th RU resources of FIG. 14 may be used as a UORA resource for the un-associated STA, and the 6th RU resource of FIG. 14 may be used as a typical resource for UL MU.

In the example of FIG. 14 , an OFDMA random access backoff (OBO) of a STA1 is decreased to 0, and the STA1 randomly selects the 2nd RU resource (AID 0, RU 2). In addition, since an OBO counter of a STA2/3 is greater than 0, an uplink resource is not allocated to the STA2/3. In addition, regarding a STA4 in FIG. 14 , since an AID (e.g., AID=3) of the STA4 is included in a trigger frame, a resource of the RU 6 is allocated without backoff.

Specifically, since the STA1 of FIG. 14 is an associated STA, the total number of eligible RA RUs for the STA1 is 3 (RU 1, RU 2, and RU 3), and thus the STA1 decreases an OBO counter by 3 so that the OBO counter becomes 0. In addition, since the STA2 of FIG. 14 is an associated STA, the total number of eligible RA RUs for the STA2 is 3 (RU 1, RU 2, and RU 3), and thus the STA2 decreases the OBO counter by 3 but the OBO counter is greater than 0. In addition, since the STA3 of FIG. 14 is an un-associated STA, the total number of eligible RA RUs for the STA3 is 2 (RU 4, RU 5), and thus the STA3 decreases the OBO counter by 2 but the OBO counter is greater than 0.

FIG. 15 illustrates an example of a channel used/supported/defined within a 2.4 GHz band.

The 2.4 GHz band may be called in other terms such as a first band. In addition, the 2.4 GHz band may imply a frequency domain in which channels of which a center frequency is close to 2.4 GHz (e.g., channels of which a center frequency is located within 2.4 to 2.5 GHz) are used/supported/defined.

A plurality of 20 MHz channels may be included in the 2.4 GHz band. 20 MHz within the 2.4 GHz may have a plurality of channel indices (e.g., an index 1 to an index 14). For example, a center frequency of a 20 MHz channel to which a channel index 1 is allocated may be 2.412 GHz, a center frequency of a 20 MHz channel to which a channel index 2 is allocated may be 2.417 GHz, and a center frequency of a 20 MHz channel to which a channel index N is allocated may be (2.407 + 0.005*N) GHz. The channel index may be called in various terms such as a channel number or the like. Specific numerical values of the channel index and center frequency may be changed.

FIG. 15 exemplifies 4 channels within a 2.4 GHz band. Each of 1st to 4th frequency domains 1510 to 1540 shown herein may include one channel. For example, the 1st frequency domain 1510 may include a channel 1 (a 20 MHz channel having an index 1). In this case, a center frequency of the channel 1 may be set to 2412 MHz. The 2nd frequency domain 1520 may include a channel 6. In this case, a center frequency of the channel 6 may be set to 2437 MHz. The 3rd frequency domain 1530 may include a channel 11. In this case, a center frequency of the channel 11 may be set to 2462 MHz. The 4th frequency domain 1540 may include a channel 14. In this case, a center frequency of the channel 14 may be set to 2484 MHz.

FIG. 16 illustrates an example of a channel used/supported/defined within a 5 GHz band.

The 5 GHz band may be called in other terms such as a second band or the like. The 5 GHz band may imply a frequency domain in which channels of which a center frequency is greater than or equal to 5 GHz and less than 6 GHz (or less than 5.9 GHz) are used/supported/defined. Alternatively, the 5 GHz band may include a plurality of channels between 4.5 GHz and 5.5 GHz. A specific numerical value shown in FIG. 16 may be changed.

A plurality of channels within the 5 GHz band include an unlicensed national information infrastructure (UNII)-1, a UNII-2, a UNII-3, and an ISM. The INII-1 may be called UNII Low. The UNII-2 may include a frequency domain called UNII Mid and UNII-2Extended. The UNII-3 may be called UNII-Upper.

A plurality of channels may be configured within the 5 GHz band, and a bandwidth of each channel may be variously set to, for example, 20 MHz, 40 MHz, 80 MHz, 160 MHz, or the like. For example, 5170 MHz to 5330 MHz frequency domains/ranges within the UNII-1 and UNII-2 may be divided into eight 20 MHz channels. The 5170 MHz to 5330 MHz frequency domains/ranges may be divided into four channels through a 40 MHz frequency domain. The 5170 MHz to 5330 MHz frequency domains/ranges may be divided into two channels through an 80 MHz frequency domain. Alternatively, the 5170 MHz to 5330 MHz frequency domains/ranges may be divided into one channel through a 160 MHz frequency domain.

FIG. 17 illustrates an example of a channel used/supported/defined within a 6 GHz band.

The 6 GHz band may be called in other terms such as a third band or the like. The 6 GHz band may imply a frequency domain in which channels of which a center frequency is greater than or equal to 5.9 GHz are used/supported/defined. A specific numerical value shown in FIG. 17 may be changed.

For example, the 20 MHz channel of FIG. 17 may be defined starting from 5.940 GHz. Specifically, among 20 MHz channels of FIG. 17 , the leftmost channel may have an index 1 (or a channel index, a channel number, etc.), and 5.945 GHz may be assigned as a center frequency. That is, a center frequency of a channel of an index N may be determined as (5.940 + 0.005*N) GHz.

Accordingly, an index (or channel number) of the 2 MHz channel of FIG. 17 may be 1, 5, 9, 13, 17, 21, 25, 29, 33, 37, 41, 45, 49, 53, 57, 61, 65, 69, 73, 77, 81, 85, 89, 93, 97, 101, 105, 109, 113, 117, 121, 125, 129, 133, 137, 141, 145, 149, 153, 157, 161, 165, 169, 173, 177, 181, 185, 189, 193, 197, 201, 205, 209, 213, 217, 221, 225, 229, 233. In addition, according to the aforementioned (5.940 + 0.005*N)GHz rule, an index of the 40 MHz channel of FIG. 17 may be 3, 11, 19, 27, 35, 43, 51, 59, 67, 75, 83, 91, 99, 107, 115, 123, 131, 139, 147, 155, 163, 171, 179, 187, 195, 203, 211, 219, 227.

Although 20, 40, 80, and 160 MHz channels are illustrated in the example of FIG. 17 , a 240 MHz channel or a 320 MHz channel may be additionally added.

Hereinafter, a PPDU transmitted/received in a STA of the present specification will be described.

FIG. 18 illustrates an example of a PPDU used in the present specification.

The PPDU of FIG. 18 may be called in various terms such as an EHT PPDU, a TX PPDU, an RX PPDU, a first type or N-th type PPDU, or the like. For example, in the present specification, the PPDU or the EHT PPDU may be called in various terms such as a TX PPDU, a RX PPDU, a first type or N-th type PPDU, or the like. In addition, the EHT PPDU may be used in an EHT system and/or a new WLAN system enhanced from the EHT system.

The PPDU of FIG. 18 may indicate the entirety or part of a PPDU type used in the EHT system. For example, the example of FIG. 18 may be used for both of a single-user (SU) mode and a multi-user (MU) mode. In other words, the PPDU of FIG. 18 may be a PPDU for one receiving STA or a plurality of receiving STAs. When the PPDU of FIG. 18 is used for a trigger-based (TB) mode, the EHT-SIG of FIG. 18 may be omitted. In other words, an STA which has received a trigger frame for uplink-MU (UL-MU) may transmit the PPDU in which the EHT-SIG is omitted in the example of FIG. 18 .

In FIG. 18 , an L-STF to an EHT-LTF may be called a preamble or a physical preamble, and may be generated/transmitted/received/obtained/decoded in a physical layer.

A subcarrier spacing of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and EHT-SIG fields of FIG. 18 may be determined as 312.5 kHz, and a subcarrier spacing of the EHT-STF, EHT-LTF, and Data fields may be determined as 78.125 kHz. That is, a tone index (or subcarrier index) of the L-STF, L-LTF, L-SIG, RL-SIG, U-SIG, and EHT-SIG fields may be expressed in unit of 312.5 kHz, and a tone index (or subcarrier index) of the EHT-STF, EHT-LTF, and Data fields may be expressed in unit of 78.125 kHz.

In the PPDU of FIG. 18 , the L-LTE and the L-STF may be the same as those in the conventional fields.

The L-SIG field of FIG. 18 may include, for example, bit information of 24 bits. For example, the 24-bit information may include a rate field of 4 bits, a reserved bit of 1 bit, a length field of 12 bits, a parity bit of 1 bit, and a tail bit of 6 bits. For example, the length field of 12 bits may include information related to a length or time duration of a PPDU. For example, the length field of 12 bits may be determined based on a type of the PPDU. For example, when the PPDU is a non-HT, HT, VHT PPDU or an EHT PPDU, a value of the length field may be determined as a multiple of 3. For example, when the PPDU is an HE PPDU, the value of the length field may be determined as “a multiple of 3”+1 or “a multiple of 3”+2. In other words, for the non-HT, HT, VHT PPDI or the EHT PPDU, the value of the length field may be determined as a multiple of 3, and for the HE PPDU, the value of the length field may be determined as “a multiple of 3”+1 or “a multiple of 3”+2.

For example, the transmitting STA may apply BCC encoding based on a ½ coding rate to the 24-bit information of the L-SIG field. Thereafter, the transmitting STA may obtain a BCC coding bit of 48 bits. BPSK modulation may be applied to the 48-bit coding bit, thereby generating 48 BPSK symbols. The transmitting STA may map the 48 BPSK symbols to positions except for a pilot subcarrier{subcarrier index -21, -7, +7, +21} and a DC subcarrier{subcarrier index 0}. As a result, the 48 BPSK symbols may be mapped to subcarrier indices -26 to -22, -20 to -8, -6 to -1, +1 to +6, +8 to +20, and +22 to +26. The transmitting STA may additionally map a signal of {-1, -1, -1, 1} to a subcarrier index{-28, -27, +27, +28}. The aforementioned signal may be used for channel estimation on a frequency domain corresponding to {-28, -27, +27, +28}.

The transmitting STA may generate an RL-SIG generated in the same manner as the L-SIG. BPSK modulation may be applied to the RL-SIG. The receiving STA may know that the RX PPDU is the HE PPDU or the EHT PPDU, based on the presence of the RL-SIG.

A universal SIG (U-SIG) may be inserted after the RL-SIG of FIG. 18 . The U-SIB may be called in various terms such as a first SIG field, a first SIG, a first type SIG, a control signal, a control signal field, a first (type) control signal, or the like.

The U-SIG may include information of N bits, and may include information for identifying a type of the EHT PPDU. For example, the U-SIG may be configured based on two symbols (e.g., two contiguous OFDM symbols). Each symbol (e.g., OFDM symbol) for the U-SIG may have a duration of 4 µs. Each symbol of the U-SIG may be used to transmit the 26-bit information. For example, each symbol of the U-SIG may be transmitted/received based on 52 data tomes and 4 pilot tones.

Through the U-SIG (or U-SIG field), for example, A-bit information (e.g., 52 un-coded bits) may be transmitted. A first symbol of the U-SIG may transmit first X-bit information (e.g., 26 un-coded bits) of the A-bit information, and a second symbol of the U-SIB may transmit the remaining Y-bit information (e.g. 26 un-coded bits) of the A-bit information. For example, the transmitting STA may obtain 26 un-coded bits included in each U-SIG symbol. The transmitting STA may perform convolutional encoding (i.e., BCC encoding) based on a rate of R=½ to generate 52-coded bits, and may perform interleaving on the 52-coded bits. The transmitting STA may perform BPSK modulation on the interleaved 52-coded bits to generate 52 BPSK symbols to be allocated to each U-SIG symbol. One U-SIG symbol may be transmitted based on 65 tones (subcarriers) from a subcarrier index -28 to a subcarrier index +28, except for a DC index 0. The 52 BPSK symbols generated by the transmitting STA may be transmitted based on the remaining tones (subcarriers) except for pilot tones, i.e., tones -21, -7, +7, +21.

For example, the A-bit information (e.g., 52 un-coded bits) generated by the U-SIG may include a CRC field (e.g., a field having a length of 4 bits) and a tail field (e.g., a field having a length of 6 bits). The CRC field and the tail field may be transmitted through the second symbol of the U-SIG. The CRC field may be generated based on 26 bits allocated to the first symbol of the U-SIG and the remaining 16 bits except for the CRC/tail fields in the second symbol, and may be generated based on the conventional CRC calculation algorithm. In addition, the tail field may be used to terminate trellis of a convolutional decoder, and may be set to, for example, “000000”.

The A-bit information (e.g., 52 un-coded bits) transmitted by the U-SIG (or U-SIG field) may be divided into version-independent bits and version-dependent bits. For example, the version-independent bits may have a fixed or variable size. For example, the version-independent bits may be allocated only to the first symbol of the U-SIG, or the version-independent bits may be allocated to both of the first and second symbols of the U-SIG. For example, the version-independent bits and the version-dependent bits may be called in various terms such as a first control bit, a second control bit, or the like.

For example, the version-independent bits of the U-SIG may include a PHY version identifier of 3 bits. For example, the PHY version identifier of 3 bits may include information related to a PHY version of a TX/RX PPDU. For example, a first value of the PHY version identifier of 3 bits may indicate that the TX/RX PPDU is an EHT PPDU. In other words, when the transmitting STA transmits the EHT PPDU, the PHY version identifier of 3 bits may be set to a first value. In other words, the receiving STA may determine that the RX PPDU is the EHT PPDU, based on the PHY version identifier having the first value.

For example, the version-independent bits of the U-SIG may include a UL/DL flag field of 1 bit. A first value of the UL/DL flag field of 1 bit relates to UL communication, and a second value of the UL/DL flag field relates to DL communication.

For example, the version-independent bits of the U-SIG may include information related to a TXOP length and information related to a BSS color ID.

For example, when the EHT PPDU is divided into various types (e.g., various types such as an EHT PPDU related to an SU mode, an EHT PPDU related to an MU mode, an EHT PPDU related to a TB mode, an EHT PPDU related to extended range transmission, or the like), information related to the type of the EHT PPDU may be included in the version-dependent bits of the U-SIG.

For example, the U-SIG may include: 1) a bandwidth field including information related to a bandwidth; 2) a field including information related to an MCS scheme applied to EHT-SIG; 3) an indication field including information regarding whether a dual subcarrier modulation (DCM) scheme is applied to EHT-SIG; 4) a field including information related to the number of symbol used for EHT-SIG; 5) a field including information regarding whether the EHT-SIG is generated across a full band; 6) a field including information related to a type of EHT-LTF/STF; and 7) information related to a field indicating an EHT-LTF length and a CP length.

Preamble puncturing may be applied to the PPDU of FIG. 18 . The preamble puncturing implies that puncturing is applied to part (e.g., a secondary 20 MHz band) of the full band. For example, when an 80 MHz PPDU is transmitted, an STA may apply puncturing to the secondary 20 MHz band out of the 80 MHz band, and may transmit a PPDU only through a primary 20 MHz band and a secondary 40 MHz band.

For example, a pattern of the preamble puncturing may be configured in advance. For example, when a first puncturing pattern is applied, puncturing may be applied only to the secondary 20 MHz band within the 80 MHz band. For example, when a second puncturing pattern is applied, puncturing may be applied to only any one of two secondary 20 MHz bands included in the secondary 40 MHz band within the 80 MHz band. For example, when a third puncturing pattern is applied, puncturing may be applied to only the secondary 20 MHz band included in the primary 80 MHz band within the 160 MHz band (or 80+80 MHz band). For example, when a fourth puncturing is applied, puncturing may be applied to at least one 20 MHz channel not belonging to a primary 40 MHz band in the presence of the primary 40 MHz band included in the 80 MHaz band within the 160 MHz band (or 80+80 MHz band).

Information related to the preamble puncturing applied to the PPDU may be included in U-SIG and/or EHT-SIG. For example, a first field of the U-SIG may include information related to a contiguous bandwidth, and second field of the U-SIG may include information related to the preamble puncturing applied to the PPDU.

For example, the U-SIG and the EHT-SIG may include the information related to the preamble puncturing, based on the following method. When a bandwidth of the PPDU exceeds 80 MHz, the U-SIG may be configured individually in unit of 80 MHz. For example, when the bandwidth of the PPDU is 160 MHz, the PPDU may include a first U-SIG for a first 80 MHz band and a second U-SIG for a second 80 MHz band. In this case, a first field of the first U-SIG may include information related to a 160 MHz bandwidth, and a second field of the first U-SIG may include information related to a preamble puncturing (i.e., information related to a preamble puncturing pattern) applied to the first 80 MHz band. In addition, a first field of the second U-SIG may include information related to a 160 MHz bandwidth, and a second field of the second U-SIG may include information related to a preamble puncturing (i.e., information related to a preamble puncturing pattern) applied to the second 80 MHz band. Meanwhile, an EHT-SIG contiguous to the first U-SIG may include information related to a preamble puncturing applied to the second 80 MHz band (i.e., information related to a preamble puncturing pattern), and an EHT-SIG contiguous to the second U-SIG may include information related to a preamble puncturing (i.e., information related to a preamble puncturing pattern) applied to the first 80 MHz band.

Additionally or alternatively, the U-SIG and the EHT-SIG may include the information related to the preamble puncturing, based on the following method. The U-SIG may include information related to a preamble puncturing (i.e., information related to a preamble puncturing pattern) for all bands. That is, the EHT-SIG may not include the information related to the preamble puncturing, and only the U-SIG may include the information related to the preamble puncturing (i.e., the information related to the preamble puncturing pattern).

The U-SIG may be configured in unit of 20 MHz. For example, when an 80 MHz PPDU is configured, the U-SIG may be duplicated. That is, four identical U-SIGs may be included in the 80 MHz PPDU. PPDUs exceeding an 80 MHz bandwidth may include different U-SIGs.

The U-SIG may be configured in unit of 20 MHz. For example, when an 80 MHz PPDU is configured, the U-SIG may be duplicated. That is, four identical U-SIGs may be included in the 80 MHz PPDU. PPDUs exceeding an 80 MHz bandwidth may include different U-SIGs.

The EHT-SIG of FIG. 18 may include control information for the receiving STA. The EHT-SIG may be transmitted through at least one symbol, and one symbol may have a length of 4 µs. Information related to the number of symbols used for the EHT-SIG may be included in the U-SIG.

The EHT-SIG may include a technical feature of the HE-SIG-B described with reference to FIG. 8 and FIG. 9 . For example, the EHT-SIG may include a common field and a user-specific field as in the example of FIG. 8 . The common field of the EHT-SIG may be omitted, and the number of user-specific fields may be determined based on the number of users.

As in the example of FIG. 8 , the common field of the EHT-SIG and the user-specific field of the EHT-SIG may be individually coded. One user block field included in the user-specific field may include information for two users, but a last user block field included in the user-specific field may include information for one user. That is, one user block field of the EHT-SIG may include up to two user fields. As in the example of FIG. 9 , each user field may be related to MU-MIMO allocation, or may be related to non-MU-MIMO allocation.

As in the example of FIG. 8 , the common field of the EHT-SIG may include a CRC bit and a tail bit. A length of the CRC bit may be determined as 4 bits. A length of the tail bit may be determined as 6 bits, and may be set to '000000'.

As in the example of FIG. 8 , the common field of the EHT-SIG may include RU allocation information. The RU allocation information may imply information related to a location of an RU to which a plurality of users (i.e., a plurality of receiving STAs) are allocated. The RU allocation information may be configured in unit of 8 bits (or N bits), as in Table 1.

The example of Table 5 to Table 7 is an example of 8-bit (or N-bit) information for various RU allocations. An index shown in each table may be modified, and some entries in Table 5 to Table 7 may be omitted, and entries (not shown) may be added.

The example of Table 5 to Table 7 relates to information related to a location of an RU allocated to a 20 MHz band. For example, ‘an index 0’ of Table 5 may be used in a situation where nine 26-RUs are individually allocated (e.g., in a situation where nine 26-RUs shown in FIG. 5 are individually allocated).

Meanwhile, a plurality or RUs may be allocated to one STA in the EHT system. For example, regarding ‘an index 60’ of Table 6, one 26-RU may be allocated for one user (i.e., receiving STA) to the leftmost side of the 20 MHz band, one 26-RU and one 52-RU may be allocated to the right side thereof, and five 26-RUs may be individually allocated to the right side thereof.

TABLE 5 Indices #1 #2 #3 #4 #5 #6 #7 #8 #9 Number of entries 0 26 26 26 26 26 26 26 26 26 1 1 26 26 26 26 26 26 26 52 1 2 26 26 26 26 26 52 26 26 1 3 26 26 26 26 26 52 52 1 4 26 26 52 26 26 26 26 26 1 5 26 26 52 26 26 26 52 1 6 26 26 52 26 52 26 26 1 7 26 26 52 26 52 52 1 8 52 26 26 26 26 26 26 26 1 9 52 26 26 26 26 26 52 1 10 52 26 26 26 52 26 26 1 11 52 26 26 26 52 52 1 12 52 52 26 26 26 26 26 1 13 52 52 26 26 26 52 1 14 52 52 26 52 26 26 1 15 52 52 26 52 52 1 16 26 26 26 26 26 106 1 17 26 26 52 26 106 1 18 52 26 26 26 106 1 19 52 52 26 106 1

TABLE 6 Indices #1 #2 #3 #4 #5 #6 #7 #8 #9 Number of entries 20 106 26 26 26 26 26 1 21 106 26 26 26 52 1 22 106 26 52 26 26 1 23 106 26 52 52 1 24 52 52 52 52 1 25 242-tone RU empty (with zero users) 1 26 106 26 106 1 27-34 242 8 35-42 484 8 43-50 996 8 51-58 2*996 8 59 26 26 26 26 26 52+26 26 1 60 26 26+52 26 26 26 26 26 1 61 26 26+52 26 26 26 52 1 62 26 26+52 26 52 26 26 1 63 26 26 52 26 52+26 26 1 64 26 26+52 26 52+26 26 1 65 26 26+52 26 52 52 1

TABLE 7 66 52 26 26 26 52+26 26 1 67 52 52 26 52+26 26 1 68 52 52+26 52 52 1 69 26 26 26 26 26+106 1 70 26 26+52 26 106 1 71 26 26 52 26+106 1 72 26 26+52 26+106 1 73 52 26 26 26+106 1 74 52 52 26+106 1 75 106+26 26 26 26 26 1 76 106+26 26 26 52 1 77 106+26 52 26 26 1 78 106 26 52+26 26 1 79 106+26 52+26 26 1 80 106+26 52 52 1 81 106+26 106 1 82 106 26+106 1

A mode in which the common field of the EHT-SIG is omitted may be supported. The mode in the common field of the EHT-SIG is omitted may be called a compressed mode. When the compressed mode is used, a plurality of users (i.e., a plurality of receiving STAs) may decode the PPDU (e.g., the data field of the PPDU), based on non-OFDMA. That is, the plurality of users of the EHT PPDU may decode the PPDU (e.g., the data field of the PPDU) received through the same frequency band. Meanwhile, when a non-compressed mode is used, the plurality of users of the EHT PPDU may decode the PPDU (e.g., the data field of the PPDU), based on OFDMA. That is, the plurality of users of the EHT PPDU may receive the PPDU (e.g., the data field of the PPDU) through different frequency bands.

The EHT-SIG may be configured based on various MCS schemes. As described above, information related to an MCS scheme applied to the EHT-SIG may be included in U-SIG. The EHT-SIG may be configured based on a DCM scheme. For example, among N data tones (e.g., 52 data tones) allocated for the EHT-SIG, a first modulation scheme may be applied to half of consecutive tones, and a second modulation scheme may be applied to the remaining half of the consecutive tones. That is, a transmitting STA may use the first modulation scheme to modulate specific control information through a first symbol and allocate it to half of the consecutive tones, and may use the second modulation scheme to modulate the same control information by using a second symbol and allocate it to the remaining half of the consecutive tones. As described above, information (e.g., a 1-bit field) regarding whether the DCM scheme is applied to the EHT-SIG may be included in the U-SIG. An HE-STF of FIG. 18 may be used for improving automatic gain control estimation in a multiple input multiple output (MIMO) environment or an OFDMA environment. An HE-LTF of FIG. 18 may be used for estimating a channel in the MIMO environment or the OFDMA environment.

The EHT-STF of FIG. 18 may be set in various types. For example, a first type of STF (e.g., 1x STF) may be generated based on a first type STF sequence in which a non-zero coefficient is arranged with an interval of 16 subcarriers. An STF signal generated based on the first type STF sequence may have a period of 0.8 µs, and a periodicity signal of 0.8 µs may be repeated 5 times to become a first type STF having a length of 4 µs. For example, a second type of STF (e.g., 2x STF) may be generated based on a second type STF sequence in which a non-zero coefficient is arranged with an interval of 8 subcarriers. An STF signal generated based on the second type STF sequence may have a period of 1.6 µs, and a periodicity signal of 1.6 µs may be repeated 5 times to become a second type STF having a length of 8 µs. Hereinafter, an example of a sequence for configuring an EHT-STF (i.e., an EHT-STF sequence) is proposed. The following sequence may be modified in various ways.

The EHT-STF may be configured based on the following sequence M.

<Equation 1>

M = {-1, -1, -1, 1, 1, 1, -1, 1, 1, 1, -1, 1, 1, -1, 1}

The EHT-STF for the 20 MHz PPDU may be configured based on the following equation. The following example may be a first type (i.e., 1x STF) sequence. For example, the first type sequence may be included in not a trigger-based (TB) PPDU but an EHT-PPDU. In the following equation, (a:b:c) may imply a duration defined as b tone intervals (i.e., a subcarrier interval) from a tone index (i.e., subcarrier index) 'a' to a tone index 'c'. For example, the equation 2 below may represent a sequence defined as 16 tone intervals from a tone index -112 to a tone index 112. Since a subcarrier spacing of 78.125 kHz is applied to the EHT-STR, the 16 tone intervals may imply that an EHT-STF coefficient (or element) is arranged with an interval of 78.125 * 16 = 1250 kHz. In addition, * implies multiplication, and sqrt() implies a square root. In addition, j implies an imaginary number.

<Equation 2>

EHT-STF(-112:16:112) = {M}*(1 + J)/sqrt(2)

EHT-STF(0) = 0

The EHT-STF for the 40 MHz PPDU may be configured based on the following equation. The following example may be the first type (i.e., 1x STF) sequence.

<Equation 3>

EHT-STF(-240:16:240) = {M, 0, -M}*(1 + j)/sqrt(2)

The EHT-STF for the 80 MHz PPDU may be configured based on the following equation. The following example may be the first type (i.e., 1x STF) sequence.

<Equation 4>

EHT-STF(-496:16:496) = {M, 1, -M, 0, -M, 1, -M} *(1 + j)/sqrt(2)

The EHT-STF for the 160 MHz PPDU may be configured based on the following equation. The following example may be the first type (i.e., 1x STF) sequence.

<Equation 5>

EHT-STF(-1008:16:1008) = {M, 1, -M, 0, -M, 1, -M, 0, -M, -1, M, 0, -M, 1, -M}*(1 + j)/sqrt(2)

In the EHT-STF for the 80+80 MHz PPDU, a sequence for lower 80 MHz may be identical to Equation 4. In the EHT-STF for the 80+80 MHz PPDU, a sequence for upper 80 MHz may be configured based on the following equation.

<Equation 6>

EHT-STF(-496:16:496) = {-M, -1, M, 0, -M, 1, -M} *(1 + j)/sqrt(2)

Equation 7 to Equation 11 below relate to an example of a second type (i.e., 2x STF) sequence.

<Equation 7>

EHT-STF(-120:8:120) = {M, 0, -M} *(1 + j)/sqrt(2)

The EHT-STF for the 40 MHz PPDU may be configured based on the following equation.

<Equation 8>

EHT-STF(-248:8:248) = {M, -1, -M, 0, M, -1, M}*(1 + j)/sqrt(2)

EHT-STF(-248) = 0

EHT-STF(248) = 0

The EHT-STF for the 80 MHz PPDU may be configured based on the following equation.

<Equation 9>

EHT-STF(-504:8:504) = {M, -1, M, -1, -M, -1, M, 0, -M, 1, M, 1, -M, 1, -M} *(1 + j)/sqrt(2)

The EHT-STF for the 160 MHz PPDU may be configured based on the following equation.

<Equation 10>

EHT-STF(-1016:16:1016) = {M, -1, M, -1, -M, -1, M, 0, -M, 1, M, 1, -M, 1, -M, 0, -M, 1, -M, 1, M, 1, -M, 0, -M, 1, M, 1, -M, 1, -M}*(1 + j)/sqrt(2)

EHT-STF(-8)=0, EHT-STF(8)=0,

EHT-STF(-1016)=0, EHT-STF(1016)=0

In the EHT-STF for the 80+80 MHz PPDU, a sequence for lower 80 MHz may be identical to Equation 9. In the EHT-STF for the 80+80 MHz PPDU, a sequence for upper 80 MHz may be configured based on the following equation.

<Equation 11>

EHT-STF(-504:8:504) = {-M, 1, -M, 1, M, 1, -M, 0, -M, 1, M, 1, -M, 1, -M} *(1 + j)/sqrt(2)

EHT-STF(-504)=0,

EHT-STF(504)=0

The EHT-LTF may have first, second, and third types (i.e., 1x, 2x, 4x LTF). For example, the first/second/third type LTF may be generated based on an LTF sequence in which a non-zero coefficient is arranged with an interval of 4/2/1 subcarriers. The first/second/third type LTF may have a time length of 3.2/6.4/12.8 µs. In addition, a GI (e.g., 0.8/⅙/3.2 µs) having various lengths may be applied to the first/second/third type LTF.

Information related to a type of STF and/or LTF (information related to a GI applied to LTF is also included) may be included in a SIG-A field and/or SIG-B field or the like of FIG. 18 .

A PPDU (e.g., EHT-PPDU) of FIG. 18 may be configured based on the example of FIG. 5 and FIG. 6 .

For example, an EHT PPDU transmitted on a 20 MHz band, i.e., a 20 MHz EHT PPDU, may be configured based on the RU of FIG. 5 . That is, a location of an RU of EHT-STF, EHT-LTF, and data fields included in the EHT PPDU may be determined as shown in FIG. 5 .

An EHT PPDU transmitted on a 40 MHz band, i.e., a 40 MHz EHT PPDU, may be configured based on the RU of FIG. 6 . That is, a location of an RU of EHT-STF, EHT-LTF, and data fields included in the EHT PPDU may be determined as shown in FIG. 6 .

Since the RU location of FIG. 6 corresponds to 40 MHz, a tone-plan for 80 MHz may be determined when the pattern of FIG. 6 is repeated twice. That is, an 80 MHz EHT PPDU may be transmitted based on a new tone-plan in which not the RU of FIG. 7 but the RU of FIG. 6 is repeated twice.

When the pattern of FIG. 6 is repeated twice, 23 tones (i.e., 11 guard tones + 12 guard tones) may be configured in a DC region. That is, a tone-plan for an 80 MHz EHT PPDU allocated based on OFDMA may have 23 DC tones. Unlike this, an 80 MHz EHT PPDU allocated based on non-OFDMA (i.e., a non-OFDMA full bandwidth 80 MHz PPDU) may be configured based on a 996-RU, and may include 5 DC tones, 12 left guard tones, and 11 right guard tones.

A tone-plan for 160/240/320 MHz may be configured in such a manner that the pattern of FIG. 6 is repeated several times.

The PPDU of FIG. 18 may be determined (or identified) as an EHT PPDU based on the following method.

A receiving STA may determine a type of an RX PPDU as the EHT PPDU, based on the following aspect. For example, the RX PPDU may be determined as the EHT PPDU: 1) when a first symbol after an L-LTF signal of the RX PPDU is a BPSK symbol; 2) when RL-SIG in which the L-SIG of the RX PPDU is repeated is detected; and 3) when a result of applying “modulo 3” to a value of a length field of the L-SIG of the RX PPDU is detected as “0”. When the RX PPDU is determined as the EHT PPDU, the receiving STA may detect a type of the EHT PPDU (e.g., an SU/MU/Trigger-based/Extended Range type), based on bit information included in a symbol after the RL-SIG of FIG. 18 . In other words, the receiving STA may determine the RX PPDU as the EHT PPDU, based on: 1) a first symbol after an L-LTF signal, which is a BPSK symbol; 2) RL-SIG contiguous to the L-SIG field and identical to L-SIG; 3) L-SIG including a length field in which a result of applying “modulo 3” is set to “0”; and 4) a 3-bit PHY version identifier of the aforementioned U-SIG (e.g., a PHY version identifier having a first value).

For example, the receiving STA may determine the type of the RX PPDU as the EHT PPDU, based on the following aspect. For example, the RX PPDU may be determined as the HE PPDU: 1) when a first symbol after an L-LTF signal is a BPSK symbol; 2) when RL-SIG in which the L-SIG is repeated is detected; and 3) when a result of applying “modulo 3” to a value of a length field of the L-SIG is detected as “1” or “2”.

For example, the receiving STA may determine the type of the RX PPDU as a non-HT, HT, and VHT PPDU, based on the following aspect. For example, the RX PPDU may be determined as the non-HT, HT, and VHT PPDU: 1) when a first symbol after an L-LTF signal is a BPSK symbol; and 2) when RL-SIG in which L-SIG is repeated is not detected. In addition, even if the receiving STA detects that the RL-SIG is repeated, when a result of applying “modulo 3” to the length value of the L-SIG is detected as “0”, the RX PPDU may be determined as the non-HT, HT, and VHT PPDU.

In the following example, a signal represented as a (TX/RX/UL/DL) signal, a (TX/RX/UL/DL) frame, a (TX/RX/UL/DL) packet, a (TX/RX/UL/DL) data unit, (TX/RX/UL/DL) data, or the like may be a signal transmitted/received based on the PPDU of FIG. 18 . The PPDU of FIG. 18 may be used to transmit/receive frames of various types. For example, the PPDU of FIG. 18 may be used for a control frame. An example of the control frame may include a request to send (RTS), a clear to send (CTS), a power save-poll (PS-poll), BlockACKReq, BlockAck, a null data packet (NDP) announcement, and a trigger frame. For example, the PPDU of FIG. 18 may be used for a management frame. An example of the management frame may include a beacon frame, a (re-)association request frame, a (re-)association response frame, a probe request frame, and a probe response frame. For example, the PPDU of FIG. 18 may be used for a data frame. For example, the PPDU of FIG. 18 may be used to simultaneously transmit at least two or more of the control frames, the management frame, and the data frame.

FIG. 19 illustrates an example of a modified transmission device and/or receiving device of the present specification.

Each device/STA of the sub-FIGS. (a)/(b) of FIG. 1 may be modified as shown in FIG. 19 . A transceiver 630 of FIG. 19 may be identical to the transceivers 113 and 123 of FIG. 1 . The transceiver 630 of FIG. 19 may include a receiver and a transmitter.

A processor 610 of FIG. 19 may be identical to the processors 111 and 121 of FIG. 1 . Alternatively, the processor 610 of FIG. 19 may be identical to the processing chips 114 and 124 of FIG. 1 .

A memory 620 of FIG. 19 may be identical to the memories 112 and 122 of FIG. 1 . Alternatively, the memory 620 of FIG. 19 may be a separate external memory different from the memories 112 and 122 of FIG. 1 .

Referring to FIG. 19 , a power management module 611 manages power for the processor 610 and/or the transceiver 630. A battery 612 supplies power to the power management module 611. A display 613 outputs a result processed by the processor 610. A keypad 614 receives inputs to be used by the processor 610. The keypad 614 may be displayed on the display 613. A SIM card 615 may be an integrated circuit which is used to securely store an international mobile subscriber identity (IMSI) and its related key, which are used to identify and authenticate subscribers on mobile telephony devices such as mobile phones and computers.

Referring to FIG. 19 , a speaker 640 may output a result related to a sound processed by the processor 610. A microphone 641 may receive an input related to a sound to be used by the processor 610.

1. Tone Plan in 802.11ax WLAN System

In the present specification, a tone plan relates to a rule for determining a size of a resource unit (RU) and/or a location of the RU. Hereinafter, a PPDU based on the IEEE 802.11ax standard, that is, a tone plan applied to an HE PPDU, will be described. In other words, hereinafter, the RU size and RU location applied to the HE PPDU are described, and control information related to the RU applied to the HE PPDU is described.

In the present specification, control information related to an RU (or control information related to a tone plan) may include a size and location of the RU, information of a user STA allocated to a specific RU, a frequency bandwidth for a PPDU in which the RU is included, and/or control information on a modulation scheme applied to the specific RU. The control information related to the RU may be included in a SIG field. For example, in the IEEE 802.11ax standard, the control information related to the RU is included in an HE-SIG-B field. That is, in a process of generating a TX PPDU, a transmitting STA may allow the control information on the RU included in the PPDU to be included in the HE-SIG-B field. In addition, a receiving STA may receive an HE-SIG-B included in an RX PPDU and obtain control information included in the HE-SIG-B, so as to determine whether there is an RU allocated to the receiving STA and decode the allocated RU, based on the HE-SIG-B.

In the IEEE 802.11ax standard, HE-STF, HE-LTF, and data fields may be configured in unit of RUs. That is, when a first RU for a first receiving STA is configured, STF/LTF/data fields for the first receiving STA may be transmitted/received through the first RU.

In the IEEE 802.11ax standard, a PPDU (i.e., SU PPDU) for one receiving STA and a PPDU (i.e., MU PPDU) for a plurality of receiving STAs are separately defined, and respective tone plans are separately defined. Specific details will be described below.

The RU defined in 11ax may include a plurality of subcarriers. For example, when the RU includes N subcarriers, it may be expressed by an N-tone RU or N RUs. A location of a specific RU may be expressed by a subcarrier index. The subcarrier index may be defined in unit of a subcarrier frequency spacing. In the 11ax standard, the subcarrier frequency spacing is 312.5 kHz or 78.125 kHz, and the subcarrier frequency spacing for the RU is 78.125 kHz. That is, a subcarrier index +1 for the RU may mean a location which is more increased by 78.125 kHz than a DC tone, and a subcarrier index -1 for the RU may mean a location which is more decreased by 78.125 kHz than the DC tone. For example, when the location of the specific RU is expressed by [-121:-96], the RU may be located in a region from a subcarrier index -121 to a subcarrier index -96. As a result, the RU may include 26 subcarriers.

The N-tone RU may include a pre-set pilot tone.

2. Null Subcarrier and Pilot Subcarrier

A subcarrier and resource allocation in the 802.11ax system will be described.

An OFDM symbol consists of subcarriers, and the number of subcarriers may function as a bandwidth of a PPDU. In the WLAN 802.11 system, a data subcarrier used for data transmission, a pilot subcarrier used for phase information and parameter tacking, and an unused subcarrier not used for data transmission and pilot transmission are defined.

An HE MU PPDU which uses OFDMA transmission may be transmitted by mixing a 26-tone RU, a 52-tone RU, a 106-tone RU, a 242-tone RU, a 484-tone RU, and a 996-tone RU.

Herein, the 26-tone RU consists of 24 data subcarriers and 2 pilot subcarriers. The 52-tone RU consists of 48 data subcarriers and 4 pilot subcarriers. The 106-tone RU consists of 102 data subcarriers and 4 pilot subcarriers. The 242-tone RU consists of 234 data subcarriers and 8 pilot subcarriers. The 484-tone RU consists of 468 data subcarriers and 16 pilot subcarriers. The 996-tone RU consists of 980 data subcarriers and 16 pilot subcarriers.

1) Null Subcarrier

As shown in FIG. 5 to FIG. 7 , a null subcarrier exists between 26-tone RU, 52-tone RU, and 106-tone RU locations. The null subcarrier is located near a DC or edge tone to protect against transmit center frequency leakage, receiver DC offset, and interference from an adjacent RU. The null subcarrier has zero energy. An index of the null subcarrier is listed as follows.

Channel Width RU Size Null Subcarrier Indices 20 MHz 26, 52 ±69, ±122 106 none 242 none 40 MHz 26, 52 ±3, ±56, ±57, ±110, ±137, ±190, ±191, ±244 106 ±3, ±110, ±137, ±244 242,484 none 80 MHz 26, 52 ±17,±70,±71,±124,±151,±204,±205, ±258,±259,±312, ±313,±366,±393,±446,±447,±500 106 ±17,±124,±151,±258,±259,±366,±393,±500 242,484 none 996 none 160 MHz 26, 52, 106 {null subcarrier indices in 80 MHz - 512, null subcarrier indices in 80 MHz + 512} 242, 484, 996, 2×996 none

A null subcarrier location for each 80 MHz frequency segment of the 80+80 MHz HE PPDU shall follow the location of the 80 MHz HE PPDU.

2) Pilot Subcarrier

If a pilot subcarrier exists in an HE-LTF field of HE SU PPDU, HE MU PPDU, HE ER SU PPDU, or HE TB PPDU, a location of a pilot sequence in an HE-LTF field and data field may be the same as a location of 4x HE-LTF. In 1x HE-LTF, the location of the pilot sequence in HE-LTF is configured based on pilot subcarriers for a data field multiplied 4 times. If the pilot subcarrier exists in 2x HE-LTF, the location of the pilot subcarrier shall be the same as a location of a pilot in a 4x data symbol. All pilot subcarriers are located at even-numbered indices listed below.

Channel Width RU Size Pilot Subcarrier Indices 20 MHz 26, 52 ±10, ±22, ±36, ±48, ±62, ±76, ±90, ±102, ±116 106, 242 ±22, ±48, ±90,±116 40 MHz 26, 52 ±10, ±24, ±36, ±50, ±64, ±78, ±90, ±104, ±116, ±130, ±144, ±158, ±170, ±184, ±198, ±212, ±224, ±238 106, 242, 484 ±10, ±36, ±78, ±104, ±144, ±170, ±212, ±238 80 MHz 26, 52 ±10, ±24, ±38, ±50, ±64, ±78, ±92, ±104, ±118, ±130, ±144, ±158, ±172, ±184, ±198, ±212, ±226, ±238, ±252, ±266, ±280, ±292, ±306, ±320, ±334, ±346, ±360, ±372, ±386, ±400, ±414, ±426, ±440, ±454, ±468, ±480, ±494 106, 242, 484 ±24, ±50, ±92, ±118, ±158, ±184, ±226, ±252, ±266, ±292, ±334, ±360, ±100, ±426, ±468, ±494 996 ±24, ±92, ±158, ±226, ±266, ±134, ±400, ±468 160 MHz 26, 52, 106, 242, 484 {pilot subcarrier indices in 80 MHz -512, pilot subcarrier indices in 80 MHz +512} 996 {for the lower 80 MHz,pilot subcarrier indices in 80 MHz -512, for the upper 80 MHz, pilot subcarrier indices in 80 MHz +512}

At 160 MHz or 80+80 MHz, the location of the pilot subcarrier shall use the same 80 MHz location for 80 MHz of both sides.

3. HE Transmit Procedure and Phase Rotation

In an 802.11ax wireless local area network (WLAN) system, transmission procedures (or transmit procedures) in a physical layer (PHY) include a procedure for an HE Single User (SU) PPDU, a transmission procedure for an HE extended range (ER) SU PPDU, a transmission procedure for an HE Multi User (MU) PPDU, and a transmission procedure for an HE trigger-based (TB) PPDU. A FORMAT field of a PHY-TXSTART.request(TXVECTOR) may be the same as HE_SU, HE_MU, HE_ER_SU or HE_TB. The transmission procedures do not describe operations of optional features, such as Dual Carrier Modulation (DCM). Among the diverse transmission procedures, FIG. 21 shows only the PHY transmission procedure for the HE SU PPDU.

FIG. 20 shows an example of a PHY transmission procedure for HE SU PPDU.

In order to transmit data, the MAC generates a PHY-TXSTART.request primitive, which causes a PHY entity to enter a transmit state. Additionally, the PHY is configured to operate in an appropriate frequency via station management through PLME. Other transmission parameters, such as HE-MCS, coding type, and transmission power are configured through a PHY-SAP by using a PHY-TXSTART.request(TXVECTOR) primitive. After transmitting a PPDU that transfers (or communicates) a trigger frame, a MAC sublayer may issue a PHY-TRIGGER.request together with a TRIGVECTOR parameter, which provides information needed for demodulating an HE TB PPDU response that is expected of the PHY entity.

The PHY indicates statuses of a primary channel and another channel via PHY-CCA.indication. The transmission of a PPDU should be started by the PHY after receiving the PHY-TXSTART.request(TXVECTOR) primitive.

After a PHY preamble transmission is started, the PHY entity immediately initiates data scrambling and data encoding. An encoding method for the data field is based on FEC_CODING, CH_BANDWIDTH, NUM_STS, STBC, MCS, and NUM_USERS parameters of the TXVECTOR.

A SERVICE field and a PSDU are encoded in a transmitter (or transmitting device) block diagram, which will be described later on. Data should be exchanged between the MAC and the PHY through a PHY-DATA.request(DATA) primitive that is issued by the MAC and PHY-DATA.confirm primitives that are issued by the PHY A PHY padding bit is applied to the PSDU in order to set a number of bits of the coded PSDU to be an integer multiple of a number of coded bits per OFDM symbol.

The transmission is swiftly (or quickly) ended by the MAC through a PHY-TXEND.request primitive. The PSDU transmission is ended upon receiving a PHY-TXEND.request primitive. Each PHY-TXEND.request primitive mat notify its reception together with a PHY-TXEND.confirm primitive from the PHY

A packet extension and/or a signal extension may exist in a PPDU. A PHY-TXEND.confirm primitive is generated at an actual end time of a most recent PPDU, an end time of a packet extension, and an end time of a signal extension.

In the PHY, a Guard Interval (GI) that is indicated together with a GI duration in a GI_TYPE parameter of the TXVECTOR is inserted in all data OFDM symbols as a solution for a delay spread.

If the PPDU transmission is completed, the PHY entity enters a receive state.

FIG. 21 shows an example of a block diagram of a transmitting device for generating each field of an HE PPDU.

In order to generate each field of the HE PPDU, the following block diagrams are used.

-   a) pre-FEC PHY padding -   b) Scrambler -   c) FEC (BCC or LDPC) encoders -   d) post-FEC PHY padding -   e) Stream parser -   f) Segment parser (for contiguous 160 MHz and non-contiguous 80+80     MHz transmission) -   g) BCC interleaver -   h) Constellation mapper -   i) DCM tone mapper -   j) Pilot insertion -   k) Replication over multiple 20 MHz (for BW>20 MHz) -   l) Multiplication by 1st column of PHE-LTF -   m) LDPC tone mapper -   n) Segment deparser -   o) Space time block code (STBC) encoder for one spatial stream -   p) Cyclic shift diversity (CSD) per STS insertion -   q) Spatial mapper -   r) Frequency mapping -   s) Inverse discrete Fourier transform (IDFT) -   f) Cyclic shift diversity (CSD) per chain insertion -   u) Guard interval (GI) insertion -   v) Windowing

FIG. 21 shows a block diagram of a transmitting device (or transmitter block diagram) that is used for generating a data field of an HE Single User (SU) PPDU having LDPC encoding applied thereto and being transmitted at a 160 MHz. If the transmitter block diagram is used for generating a data field of an HE SU PPDU that is transmitted in an 80+80 MHz band, a segment deparser is not used as shown in FIG. 21 . That is, the block diagram of the transmitter (or transmitting device) is used per 80 MHz band in a situation where the band is divided into an 80 MHz band and another 80 MHz band by using a segment parser.

Referring to FIG. 21 , an LDPC encoder may encode a data field (or data bitstream). The data bitstream input to the LDPC encoder may be scrambled by a scrambler.

A stream parser divides the data bitstream encoded by the LDPC encoder into a plurality of spatial streams. At this time, an encoded data bitstream divided into each spatial stream may be referred to as a spatial block. The number of spatial blocks may be determined by the number of spatial streams used to transmit a PPDU and may be set to be equal to the number of spatial streams.

The stream parser divides each spatial block into at least one or more data segments. As shown in FIG. 21 when the data field is transmitted in a 160 MHz band, the 160 MHz band is divided into two 80 MHz bands, and the data field is divided into a first data segment and a second data segment for the respective 80 MHz bands. Afterward, the first and second data segments may be constellation mapped to the respective 80 MHz bands and may be LDPC mapped.

In HE MU transmission, except that cyclic shift diversity (CSD) is performed based on the information on a space-time stream start index for the corresponding user, a PPDU encoding processor is run independently in a Resource Unit (RU) for each user even for an input to a space mapping block. All the user data of the RU are mapped by being coupled to a transmission chain of the space mapping block.

In the 802.11ax, phase rotation may be applied to the field from the legacy preamble to the field just before the HE-STF, and a phase rotation value may be defined in units of 20 MHz bands. In other words, phase rotation may be applied to L-STF, L-LTF, L-SIG, RL-SIG, HE-SIG-A, and HE-SIG-B among fields of the HE PPDU defined in the 802.11ax.

The L-STF field of the HE PPDU may be constructed as follows.

-   a) Determine the channel bandwidth from the TXVECTOR parameter     CH_BANDWIDTH. -   b) Sequence generation: Generate the L-STF sequence over the channel     bandwidth as described in 27.3.11.3 (L-STF). Apply a 3 dB power     boost if transmitting an HE ER SU PPDU as described in 27.3.11.3     (L-STF). -   c) Phase rotation: Apply appropriate phase rotation for each 20 MHz     subchannel as described in 27.3.10 (Mathematical description of     signals) and 21.3.7.5(Definition of tone rotation). -   d) CSD per STS: If the TXVECTOR parameter BEAM_CHANGE is 0, apply     CSD per STS for each space-time Stream and frequency segment as     described in 27.3.11.2.2 (Cyclic shift for HE modu-lated fields). -   e) Spatial mapping: If the TXVECTOR parameter BEAM_CHANGE is 0,     apply the 0.1 matrix and the Q matrix as described in 27.3.11.3     (L-STF). -   f) IDFT: Compute the inverse discrete Fourier transform. -   g) CSD per chain: If the TXVECTOR parameter BEAM_CHANGE is 1 or not     present apply CSD per chain for each transmit chain and frequency     segment as described in 27.3.11.2.1 (Cyclic shift for pre-HE     modulated fields). -   h) Insert GI and apply windowing: Prepend a GI (T_(GL,Pre-HB)) and     apply windowing as described in 27.3.10 (Mathematical description of     signals). -   i) Analog and RF. Upconvert the resulting complex baseband waveform     associated with each transmit chain to an RF signal according to the     center frequency of the desired channel and transmit Refer to     27.3.10 (Mathematical description of signals) and 27.3.11 (HE     preamble) for details.

The L-LTF field of the HE PPDU may be constructed as follows.

-   a) Determine the channel bandwidth from the TXVECTOR parameter     CH_BANDWIDTH. -   b) Sequence generation: Generate the L-LTF sequence over the channel     bandwidth as described in 27.3.11.4 (L-LTF). Apply a 3 dB power     boost if transmitting an HE ER SU PPDU as described in 27.3.11.4     (L-LTF). -   c) Phase rotation: Apply appropriate phase rotation for each 20 MHz     subchannel as described in 27.3.10 (Mathematical description of     signals) and 21.3.7.5 (Definition of tone rotation). -   d) CSD per STS: If the TXVECTOR parameter BEAM_CHANGE is 0. apply     CSD per STS for each space-time stream and frequency segment as     described in 27.3.11.2.2 (Cyclic shift for HE modulated fields)     before spatial mapping. -   c) Spatial mapping: If the TXVECTOR parameterBEAM_CHANGE. is 0,     apply the A matrix and the Q matrix as described in 27.3.11.4     (L-LTF). -   f) 1DFT: Compute the inverse discrete Fourier transform. -   g) CSD per chain: If the TXVECTOR parameter BEAM_CHANGE is 1 or not     present, apply CSD per chain for each transmit chain and frequency     segment as described in 27.3.11.2.1 (Cyclic shift for pre-HE     modulated fields). -   h) Insert GI and apply windowing: Prepend a GI (T_(GI,L-LFF)) and     apply windowing as described in 27.3.10 (Mathematical description of     signals). -   i) Analog and RF: Upconvert the resulting complex baseband waveform     associated with each transmit chain to an RF signal according to the     carrier frequency of the desired channel and transmit. Refer to     27.3.10 (Mathematical description of signals) and 27.3.11 (HE     preamble) for details.

The L-SIG field of the HE PPDU may be constructed as follows.

-   a) Set the RATE subfield in the SIGNAL field to 6 Mb/s. Set the     LENGTH, Parity, and Tail Helds in the SIGNAL field as described in     27.3.11.5 (L-S1G). -   b) BCC encoder: Encode the SIGNAL field by a conventional encoder     at: the rate of R ½ as described in 27.3.12.5.1 (BCC coding and     puncturing). -   c) BCC interleaver: Interleave as described in 17.3.5.7 (BCC     interleavers). -   d) Constellation Mapper: BPSK modulate as described in 27.3.12.9     (Constellation mapping). -   e) Pilot insertion: Insert pilots as described in 27.3.11.5 (L-SIG). -   f) Extra subcarrier insertion: Four extra subcarriers are inserted     at k ∈ {-28, -27, 27, 28} for channel estimation purpose and the     values on these four extra subcarriers are {-1, -1, -1, 1}.     respectively. Apply a 3 dB power boost to the four extra subcarriers     if transmitting an HE ER SU PPDU as described in 27.3.11.5 (L-SIG). -   g) Duplication and phase rotation: Duplicate the L-SIG field over     each occupied 20 MHz subchannel of the channel bandwidth. Apply     appropriate phase rotation for each occupied 20 MHz subchannel as     described in 27.3.10 (Mathematical description of signals) and     21.3.7.5 (Definition of tone rotation). -   h) CSD per STS: If the TXVECTOR parameter BEAM_CHANGE is 0. apply     CSD per STS for each space-time stream and frequency segment as     described in 27.3.11.2.2 (Cyclic shift for HE modulated fields)     before spatial mapping. -   i) Spatial mapping: If the TXVECTOR parameter BEAM_CHANGE is 0,     apply the A matrix and Q matrix as described in 27.3.11.5 (L-SIG). -   j) IDFT: Compute the inverse discrete Fourier transform. -   k) CSD per chain: If the TXVECTOR parameter BEAM_CHANGE is 1 or not     present, apply CSD per chain for each transmit chain and frequency     segment as described in 27.3.11.2.1 (Cyclic shift for pm-EIE     modulated fields). -   l) Insert GI and apply windowing: Prepend a GI (T_(GLPre-HE)) and     apply windowing as described in 27.3.10 (Mathematical description of     signals). -   in) Analog and RF: Upconvert the resulting complex baseband waveform     associated with each transmit chain. Refer to 27.3.10 (Mathematical     description of signals) and 27.3.11 (HE preamble) for details.

The RL-SIG field of the HE PPDU may be constructed as follows.

-   a) Set the RATE subfield in the repeat SIGNAL field to 6 Mb/s. Set     the LENGTH Parity, and Tail fields in the repeat SIGNAL field as     described in 27.3.11.6 (RL-SIG). -   b) BCC encoder: Encode the repeat SIGNAL field by a convolutional     encoder at the rate of R = ½ as described in 27.3.12.5.1 (BCC coding     and puncturing). -   c) BCC interleaver: Interleave as described in 17.3.5.7 (BCC     interleavers). -   d) Constellation Mapper BPSK modulate as described in 27.3.12.9     (Constellation mapping). -   e) Pilot insertion: Insert pilots as described in 27.3.11.6     (RL-SIG). -   f) Extra subcarrier insertion: Four extra subcarriers are inserted     at k ∈ {-28, -27, 27, 28} for channel estimation purpose and the     values on these four extra subcarriers are {-1, -1, -1, 1},     respectively. Apply a 3 dB power boost to the four extra subcarriers     if transmitting an HE ER SU PPDU as described in 27.3.11.6 (RL-SIG). -   g) Duplication and phase rotation: Duplicate the RL-SIG field over     each occupied 20 MHz subchannel of the channel bandwidth. Apply     appropriate phase rotation for each occupied 20 MHz subchannel as     described in 27.3.10 (Mathematical description of signals) and     21.3.7.5 (Definition of tone rotation). -   h) CSD per STS: If the TXVECTOR parameter BEAM_CHANGE is 0, apply     CSD per STS for each space-time stream and frequency segment as     described in 27.3.11.2.2 (Cyclic shift for HE modulated fields)     before spatial mapping. -   i) Spatial mapping: If the TXVECTOR parameter BEAM_CHANGE is 0,     apply the A matrix and the Q matrix as described in 27.3.11.6     (RL-SIG). -   j) IDFT: Compute the inverse discrete Fourier transform. -   k) CSD per chain: If the TXVECTOR parameter BEAM_CHANGE is 1 or not     present, apply CSD per chain for each transmit chain and frequency     segment as described in 27.3.11.2.1 (Cyclic shift for pre-HE     modulated fields). -   l) Insert GI and apply windowing: Prepend a GI (T_(GI,Pre-HE)) and     apply windowing as described in 27.3.10 (Mathematical description of     signals). -   m) Analog and RF: Upconvert the resulting complex baseband waveform     associated with each transmit chain. Refer to 27.3.10 (Mathematical     description of signals) and 27.3.11 (HE preamble) for details.

4. Embodiment Applicable to the Present Disclosure

In the wireless LAN 802.11 system, to increase peak throughput, it is considered to use a wider band than the existing llax or to transmit an increased stream by using more antennas. In addition, the present specification also considers a method of using aggregation of various bands. In addition, the present specification attempts to improve performance by applying preamble puncturing even in non-OFDMA transmission.

This specification proposes a method of indicating bandwidth and preamble puncturing in U-SIG in EHT PPDU transmission. Since preamble puncturing is applied to a multi-user (MU) PPDU, a trigger-based (TB) PPDU, and a single-user (SU) PPDU, it can be equally applied to all PPDUs.

FIG. 22 shows an example of an EHT PPDU format.

FIG. 23 shows an example of a U-SIG format.

The U-SIG is divided into a version independent field and a version dependent field as shown in FIG. 23 .

EHT-SIG may carry various common information.

The transmitter may indicate the bandwidth using the Bandwidth field. Bandwidth field may be included in the version independent / dependent field of Universal-SIG (U-SIG) or EHT-SIG, but it is preferred that the receiving end belongs to the version independent / dependent field of U-SIG for quick acquisition of bandwidth information. If the bandwidth field belongs to the version independent field, it can be universally used in Wi-Fi after EHT. Additionally, a preamble puncturing pattern within a corresponding 80 MHz in each 80 MHz may also be indicated together with the bandwidth field. This is called the 80 MHz preamble puncturing pattern field, but other names may be used. This may help STAs decoding a specific 80 MHz to decode the EHT-SIG. Therefore, assuming that such information is loaded in the U-SIG, the configuration of the U-SIG may be changed every 80 MHz. Alternatively, a field indicating a preamble puncturing pattern applied to the entire PPDU may be located together with the bandwidth field. This field is called a preamble puncturing field, and when it is used, the 80 MHz preamble puncturing pattern field may not be used.

In addition, the version independent field may include a 3-bit version identifier indicating a Wi-Fi version after 802.11 be and 802.11 be, a 1-bit DL/UL field, a BSS color, a TXOP duration, and the like. The version dependent field may include information such as PPDU type, Bandwidth, and 80 MHz preamble puncturing pattern. (Information on the bandwidth, 80 MHz preamble puncturing pattern may be carried in the version independent field.) The SU PPDU may be indicated in the PPDU type field and may be the same element as the MU PPDU. In addition, in U-SIG, two symbols are jointly encoded, and each 20 MHz consists of 52 data tones and 4 pilot tones. In addition, U-SIG is modulated in the same way as HE-SIG-A. That is, the U-SIG is modulated with a BPSK ½ code rate. In addition, the EHT-SIG consists only of a common field in the case of an SU PPDU, but may be divided into a common field and a user specific field in the case of an MU PPDU, and may be encoded as a variable MCS. EHT-SIG can have 1 2 1 2 ... structure in units of 20 MHz as in the existing 11ax. (EHT-SIG may be configured in a different structure. For example, EHT-SIG may be configured in “1 2 3 4 ... or 1 2 1 2 3 4 3 4 ... structure”. In addition, EHT-SIG is 80 MHz unit may be configured, and EHT-SIG may be duplicated in units of 80 MHz in a bandwidth of 80 MHz or more.) In the case of an SU PPDU, it may have the same EHT-SIG structure as in the case of an MU PPDU, or the EHT-SIG may be duplicated and located in the same every 20/80 MHz.

4.1. Bandwidth Field

In 802.11be, SU PPDU can be transmitted using 240/160+80/320/160+160 MHz in addition to 20/40/80/80+80/160 MHz, which is the bandwidth of the existing 11ax, and the bandwidth field can be configured in various examples as follows.

4.1.1. Example 1

Using 3 bits, it can be expressed as follows.

-   0: 20 MHz -   1: 40 MHz -   2: 80 MHz -   3: 160 MHz and 80+80 MHz -   4: 240 MHz and 160+80 MHz -   5: 320 MHz and 160+160 MHz -   6~7: reserved

Since information about the preamble puncturing pattern can be acquired from the EHT-SIG, only bandwidth information can be indicated in the bandwidth field. Although there is a disadvantage that the receiving end acquires relatively late whether or not preamble puncturing has been applied, the overhead of the bandwidth field can be reduced. If the 240/160+80 MHz channel is already fixed by channelization or not known by the MAC indicator (If the 240/160+80 MHz channel is already fixed by channelization or known by the MAC indicator, it will be referred to as determined 240/160+80 MHz), information on this can also be acquired from the Preamble puncturing pattern field. In addition, if it is not determined 240/160+80 MHz, all STAs that transmit and receive must have 320/160+160 MHz capability to indicate bandwidth information in the bandwidth field.

4.1.2. Example 2

Using 4 bits, it can be expressed as follows.

-   0: 20 MHz -   1: 40 MHz -   2: 80 MHz non-preamble puncturing mode -   3: 160 MHz and 80+80 MHz non-preamble puncturing mode -   4: 240 MHz and 160+80 MHz non-preamble puncturing mode -   5: 320 MHz and 160+160 MHz non-preamble puncturing mode -   6: preamble puncturing in 80 MHz -   7: preamble puncturing in 160 MHz or 80+80 MHz -   8: preamble puncturing in 240 MHz or 160+80 MHz -   9: preamble puncturing in 320 MHz or 160+160 MHz -   10~15: reserved

In this embodiment, there are 1 bit more bits of the Bandwidth field than in Example 1, but the receiving end can learn whether preamble puncturing is applied relatively quickly. However, if it is not determined 240/160+80 MHz, this information can be acquired from the Preamble puncturing pattern field, so there is a disadvantage that the acquisition may be delayed. In addition, if it is not determined 240/160+80 MHz, all STAs that transmit and receive must have 320/160+160 MHz capability to indicate bandwidth information in the bandwidth field.

4.1.3. Example 3

Using 3 bits, it can be expressed as follows.

-   0: 20 MHz -   1: 40 MHz -   2: 80 MHz -   3: 160 MHz and 80+80 MHz -   4: 320 MHz and 160+160 MHz -   5~7: reserved

This embodiment can be used when it is not determined 240/160+80 MHz, and when the PPDU is transmitted at 240/160+80 MHz, it can be viewed as a special case of 320/160+160 MHz. That is, the bandwidth field may be set to 320 MHz and 160 + 160 MHz, and detailed information on this may be acquired from the preamble puncturing pattern. Although the overhead of the bandwidth field is small, there are disadvantages in that the receiving end acquires information of whether preamble puncturing is applied and 240/160+80 MHz information relatively late.

4.1.4. Example 4

Using 3 bits, it can be expressed as follows.

-   0: 20 MHz -   1: 40 MHz -   2: 80 MHz non-preamble puncturing mode -   3: 160 MHz and 80+80 MHz non-preamble puncturing mode -   4: 320 MHz and 160+160 MHz non-preamble puncturing mode -   5: preamble puncturing in 80 MHz -   6: preamble puncturing in 160 MHz or 80+80 MHz -   7: preamble puncturing in 320 MHz or 160+160 MHz

This embodiment can be used when it is not determined 240/160+80 MHz, and when the PPDU is transmitted at 240/160+80 MHz, it can be viewed as a special case of 320/160+160 MHz. That is, the bandwidth field may be set to 320 MHz and 160 + 160 MHz, and detailed information on this may be acquired from the preamble puncturing pattern. Although the bandwidth field overhead is small, there is a disadvantage that the receiver acquires information of 240/160+80 MHz relatively late.

4.1.5. Example 5

FIG. 24 shows an example of a 320 MHz channel configuration.

In FIG. 24 , 80_1 means primary 80 and 80_2 means secondary 80. 80_3 means an 80 MHz channel in the position corresponding to 80_1 among the secondary 160 (that is, the channel corresponding to the primary 80), and 80_4 means an 80 MHz channel in the position corresponding to 80_2 among the secondary 160 (i.e., the channel corresponding to 80_2), the channel at the position corresponding to secondary 80). Alternatively, the secondary 160 at the low frequency can be called 80_3, and the secondary 160 at the high frequency can be called 80_4. Or 80_1 means 80 MHz in the lowest frequency, 80_2 means 80 MHz in the second low frequency, 80_3 means 80 MHz in the second high frequency, and 80_4 means 80 MHz in the highest frequency. In this specification, it will be defined and described as a channel in a position corresponding to primary / secondary 80. Also, the positions of the primary and secondary 80 may be changed, and FIG. 25 is an example.

FIG. 25 shows another example of a 320 MHz channel configuration.

In this case, 240/160+80 MHz may consist of three 80 MHz channels including the primary 80, and thus three combinations are possible.

Mode 1: (80_1, 80_2, 80_3), Mode 2: (80_1, 80_2, 80_4), Mode 3: (80_1, 80_3, 80_4)

In the case of Determined 240/160+80 MHz, it is determined by one of the three combinations, but if it is not determined 240/160+80 MHz, the indication for the above three combinations can be performed in the bandwidth field and can be expressed using 3 bits as follows.

-   0: 20 MHz -   1: 40 MHz -   2: 80 MHz -   3: 160 MHz and 80+80 MHz -   4: 240 MHz and 160+80 MHz mode 1 -   5: 240 MHz and 160+80 MHz mode 2 -   6: 240 MHz and 160+80 MHz mode 3 -   7: 320 MHz and 160+160 MHz

This embodiment has a disadvantage in that it can be applied only to cases other than determined 240/160+80 MHz and can simplify the preamble puncturing pattern field. This will be dealt with in Section 4.2. Although the number of bits is smaller than that of Example 6 below, this embodiment has a disadvantage in that the receiver acquires whether preamble puncturing is applied relatively late.

4.1.6. Example 6

Using 4 bits, it can be expressed as follows.

-   0: 20 MHz -   1: 40 MHz -   2: 80 MHz non-preamble puncturing mode -   3: 160 MHz and 80+80 MHz non-preamble puncturing mode -   4: 240 MHz and 160+80 MHz non-preamble puncturing mode 1 -   5: 240 MHz and 160+80 MHz non-preamble puncturing mode 2 -   6: 240 MHz and 160+80 MHz non-preamble puncturing mode 3 -   7: 320 MHz and 160+160 MHz non-preamble puncturing mode -   8: preamble puncturing in 80 MHz -   9: preamble puncturing in 160 MHz or 80+80 MHz -   10: preamble puncturing in 240 MHz or 160+80 MHz mode 1 -   11: preamble puncturing in 240 MHz or 160+80 MHz mode 2 -   12: preamble puncturing in 240 MHz or 160+80 MHz mode 3 -   13: preamble puncturing in 320 MHz or 160+160 MHz -   14~15: reserved

This embodiment can be applied only when it is not determined 240/160+80 MHz. Although the overhead is large, it has the advantage of being able to acquire the 80 MHz channel used for 240/160+80 MHz relatively quickly, whether preamble puncturing is applied or not.

4.1.7. Example 7

Using 4 bits, it can be expressed as follows.

-   0: 20 MHz -   1: 40 MHz -   2: 80 MHz non-preamble puncturing mode -   3: 160 MHz and 80+80 MHz non-preamble puncturing mode -   4: 240 MHz and 160+80 MHz non-preamble puncturing mode 1 -   5: 240 MHz and 160+80 MHz non-preamble puncturing mode 2 -   6: 240 MHz and 160+80 MHz non-preamble puncturing mode 3 -   7: 320 MHz and 160+160 MHz non-preamble puncturing mode -   8: preamble puncturing in 80 MHz -   9: preamble puncturing in 160 MHz or 80+80 MHz -   10: preamble puncturing in 240 MHz or 160+80 MHz -   11: preamble puncturing in 320 MHz or 160+160 MHz -   12~15: reserved

In this embodiment, in the preamble puncturing of 240/160+80 MHz, three 80 MHz used may be indicated in the EHT-SIG or the like. The 80 MHz preamble puncturing pattern field may be used for other purposes during non-preamble puncturing.

4.2. 80 MHz Preamble Puncturing Pattern Field

Since each 80 MHz can have a different puncturing pattern, the 80 MHz preamble puncturing pattern field in the U-SIG for each 80 MHz can be configured differently. If EHT-SIG has a 1 2 1 2 ... structure (or 1 2 1 2 3 4 3 4 ... structure) like the existing 11ax, in order to guarantee decoding only for channels 1 and 2 (or 3 and 4), EHT-SIG may indicate a simple puncturing pattern or may indicate an accurate puncturing pattern. If the EHT-SIG is not 1 2 1 2 structure (or 1 2 1 2 3 4 3 4 ... structure) and is encoded in an 80 MHz band, accurate indication of a puncturing pattern may be advantageous.

4.2.1. Example 1

Structure using 1 bit

0: lowest 20 MHz and second lowest 20 MHz puncturing

1: Highest 20 MHz and second highest 20 MHz puncturing

Bit descriptions are interchangeable and can be used in any EHT-SIG structure. A limited puncturing pattern is considered considering the case where the EHT-SIG is 1 2 1 2 ... structure (or 1 2 1 2 3 4 3 4 ... structure). The present embodiment may not be good in terms of efficiency because puncturing is limited, but overhead is small. Only the description of one bit of the two is reflected, and the description of all channel non-puncturing bits may be used for the remaining elements.

4.2.2. Example 2

Structure using 1 bit

0: lowest 20 MHz and highest 20 MHz puncturing

1: 2nd low 20 MHz and 2nd high 20 MHz puncturing

Bit descriptions are interchangeable and can be used in any EHT-SIG structure. A limited puncturing pattern is considered considering the case where the EHT-SIG is 1 2 1 2 ... structure (or 1 2 1 2 3 4 3 4 ... structure). The present embodiment may not be good in terms of efficiency because puncturing is limited, but overhead is small. Only the description of one bit of the two is reflected, and the description of all channel non-puncturing bits may be used for the remaining elements.

4.2.3. Example 3

Structure using 2 bits

0: lowest 20 MHz and next lowest 20 MHz puncturing

1: Highest 20 MHz and then highest 20 MHz puncturing

2: Lowest 20 MHz and highest 20 MHz puncturing

3: second low 20 MHz and second high 20 MHz puncturing

Bit descriptions are interchangeable and can be used in any EHT-SIG structure. A limited puncturing pattern is considered considering the case where the EHT-SIG is 1 2 1 2 ... structure (or 1 2 1 2 3 4 3 4 ... structure). Only descriptions of three bits among the four bits elements are reflected, and the remaining one element may be used as descriptions of all channel non-puncturing bits.

4.2.4. Example 4

Structure using 2 bits

0: lowest 20 MHz and next lowest 20 MHz puncturing

1: Highest 20 MHz and then highest 20 MHz puncturing

2: All channels non-puncturing

3: reserved

Bit descriptions are interchangeable and can be used in any EHT-SIG structure. A limited puncturing pattern is considered considering the case where the EHT-SIG is 1 2 1 2 ... structure (or 1 2 1 2 3 4 3 4 ... structure). The present embodiment may not be good in terms of efficiency because puncturing is limited, but overhead is small.

4.2.5. Example 5

Structure using 2 bits

0: lowest 20 MHz and highest 20 MHz puncturing

1: second low 20 MHz and second high 20 MHz puncturing

2: All channels non-puncturing

3: reserved

Bit descriptions are interchangeable and can be used in any EHT-SIG structure. A limited puncturing pattern is considered considering the case where the EHT-SIG is 1 2 1 2 ... structure (or 1 2 1 2 3 4 3 4 ... structure). The present embodiment may not be good in terms of efficiency because puncturing is limited, but overhead is small.

4.2.6. Example 6

Structure using 3 bits

0: lowest 20 MHz and second lowest 20 MHz puncturing

1: Highest 20 MHz and second highest 20 MHz puncturing

2: Lowest 20 MHz and highest 20 MHz puncturing

3: second lowest 20 MHz and second highest 20 MHz puncturing

4: All channels non-puncturing

5-7: reserved

Bit descriptions are interchangeable and can be used in any EHT-SIG structure. A limited puncturing pattern is considered considering the case where the EHT-SIG is 1 2 1 2 ... structure (or 1 2 1 2 3 4 3 4 ... structure).

4.2.7. Example 7

Structure using 2 bits

0: lowest 20 MHz and second lowest 20 MHz puncturing

1: second lowest 20 MHz and second lowest 20 MHz puncturing

2: third lowest 20 MHz and highest 20 MHz puncturing

3: All channels non-puncturing

Bit descriptions are interchangeable and can be used in any EHT-SIG structure. A limited puncturing pattern is considered considering the case where the EHT-SIG is 1 2 1 2 ... structure (or 1 2 1 2 3 4 3 4 ... structure).

4.2.8. Example 8

Bit map method using 4 bits

A total of 16 patterns are displayed from 0000 to 1111. 0 means puncturing and 1 means no puncturing. The descriptions of 0 and 1 can be interchanged, which can be useful when encoded in units of 80 MHz. Various puncturing patterns can be considered, which is good in terms of efficiency, but has the largest overhead.

As the corresponding preamble puncturing pattern, only the following can be considered.

1111, 0111, 1011, 1101, 1110, 0011, 1100

This may be a possible method considering the limited preamble puncturing situation of non-OFDMA or SU transmission.

Alternatively, only the following preamble puncturing pattern may be considered.

1111, 0111, 1011, 1101, 1110, 0011, 1100, 1001

This may be a preferable method when considering flexible preamble puncturing of OFDMA or MU transmission as well as limited preamble puncturing situation of non-OFDMA or SU transmission.

In addition, various preamble puncturing methods may be applied.

The above proposal is particularly applicable to OFDMA or MU situations and enables flexible preamble puncturing for each 80 MHz. In case of Non-OFDMA or SU transmission, limited preamble puncturing is defined, which may be indicated in a different way. (For example, it can be indicated by using more bits. ex) The method of 4.3)

4.2.9. Example 9

Structure using 1 bit

0: The lowest 20 MHz and the next lowest 20 MHz non-puncturing, other channels are puncturing or non-puncturing

1: The highest 20 MHz and the next highest 20 MHz non-puncturing, other channels are puncturing or non-puncturing

Bit descriptions can be interchanged, and this is a case in which an exact puncturing pattern is not indicated. This embodiment may be particularly useful when EHT-SIG is 1 2 1 2 ... structure (or 1 2 1 2 3 4 3 4 ... structure). Puncturing is limited and can be applied only in limited situations.

4.2.10. Example 10

Structure using 1 bit

0: Lowest 20 MHz and highest 20 MHz non-puncturing, other channels are puncturing or non-puncturing

1: Second lowest 20 MHz and second highest 20 MHz non-puncturing, other channels are puncturing or non-puncturing

Bit descriptions can be interchanged, and this is a case in which an exact puncturing pattern is not indicated. This embodiment may be particularly useful when EHT-SIG is 1 2 1 2 ... structure (or 1 2 1 2 3 4 3 4 ... structure). Puncturing is limited and can be applied only in limited situations.

4.2.11. Example 11

Structure using 2 bits

0: The lowest 20 MHz and the next lowest 20 MHz non-puncturing, other channels are puncturing or non-puncturing

1: The highest 20 MHz and the next highest 20 MHz non-puncturing, other channels are puncturing or non-puncturing

2: Lowest 20 MHz and highest 20 MHz non-puncturing, other channels are puncturing or non-puncturing

3: Second low 20 MHz and second high 20 MHz non-puncturing, other channels are puncturing or non-puncturing

Bit descriptions can be interchanged, and this is a case in which an exact puncturing pattern is not indicated. This embodiment may be particularly useful when EHT-SIG is 1 2 1 2 ... structure (or 1 2 1 2 3 4 3 4 ... structure). Puncturing is limited and can be applied only in limited situations.

4.2.12. Example 12

Structure using 2 bits

0: Lowest 20 MHz and second lowest 20 MHz non-puncturing, other channels are puncturing or non-puncturing

1: 2nd lowest 20 MHz and 3rd lowest 20 MHz non-puncturing, other channels are puncturing or non-puncturing

2: Third lowest 20 MHz and highest 20 MHz non-puncturing, other channels are puncturing or non-puncturing

3: reserved

Bit descriptions can be interchanged, and this is a case in which an exact puncturing pattern is not indicated. This embodiment may be particularly useful when EHT-SIG is 1 2 1 2 ... structure (or 1 2 1 2 3 4 3 4 ... structure). Puncturing is limited and can be applied only in limited situations.

4.2.13. Example 13

Structure using 3 bits

0: lowest 20 MHz puncturing

1: Second lowest 20 MHz puncturing

2: third lowest 20 MHz puncturing

3: Highest 20 MHz puncturing

4: lowest 20 MHz and second lowest 20 MHz puncturing

5: second lowest 20 MHz and third lowest 20 MHz puncturing

6: third lowest 20 MHz and highest 20 MHz puncturing

7: All channels non-puncturing

Bit descriptions are interchangeable and can be used in all EHT-SIG structures. It cannot be used in a situation where 20 MHz and continuous 40 MHz puncturing are considered, and preamble puncturing of 60 MHz or higher is applied. OFDMA or MU transmission uses the same configuration as above, but in non-OFDMA or SU transmission, the description of element 5 is changed from ‘second lowest 20 MHz and third lowest 20 MHz puncturing’ to ‘non-puncturing in full bandwidth (meaning whole bandwidth, not the corresponding 80 MHz channel)’. It can be expressed by changing the order as shown in the table below. (o: non-punctured 20 MHz channel, x: punctured 20 MHz channel)

TABLE 8 Bit OFDMA Non-OFDMA [2] 000 oooo oooo 001 xooo xooo 010 oxoo oxoo 011 ooxo ooxo 100 ooox ooox 101 xxoo xxoo 110 ooxx ooxx 111 oxxo No puncture across the whole BW

In case of Non-OFDMA or SU transmission, limited preamble puncturing is defined, which may be indicated in a different way. (For example, it can be indicated by using more bits. Ex) The method of 4.3)

4.2.14. Example 14

Structure using 3 bits

0: lowest 20 MHz and second lowest 20 MHz puncturing

1: second lowest 20 MHz and third lowest 20 MHz puncturing

2: third lowest 20 MHz and highest 20 MHz puncturing

3: Low successive three 20 MHz channel puncturing

4: High successive three 20 MHz channel puncturing

5: All channels non-puncturing

6-7: reserved

Bit descriptions are interchangeable and can be used in any EHT-SIG structure. Since continuous 60 MHz and 40 MHz puncturing is considered, it cannot be used in a situation where 20 MHz preamble puncturing is applied.

4.2.15. Example 15

Structure using 3 bits

0: lowest 20 MHz puncturing

1: Second lowest 20 MHz puncturing

2: third lowest 20 MHz puncturing

3: Highest 20 MHz puncturing

4: Low successive three 20 MHz channel puncturing

5: High successive three 20 MHz channel puncturing

6: All channels non-puncturing

7: reserved

Bit descriptions are interchangeable and can be used in any EHT-SIG structure. Since 20 MHz and continuous 60 MHz puncturing are considered, it cannot be used in a situation where 40 MHz preamble puncturing is applied.

The various 80 MHz preamble puncturing pattern fields proposed above can be particularly applied to OFDMA or MU situations, and enables flexible preamble puncturing for each 80 MHz. In case of non-OFDMA or SU transmission, limited preamble puncturing is defined, which may be indicated in a different way. (For example, it can be indicated by using more bits. Ex) The method of 4.3)

4.3. Preamble Puncturing Pattern Field

Preamble puncturing information applied to the PPDU may be carried. In this case, the bandwidth field may consist of “4.1.1. Example 1 and 4.1.2. Example 2”, and the 80 MHz preamble puncturing pattern field of 4.2. may not be used.

A case having a limited preamble puncturing pattern in each bandwidth may be considered as follows. This will be referred to as the basic preamble puncturing pattern. Below, O or X means that a specific 20 MHz channel is not punctured or punctured, and is expressed in order from a low frequency 20 MHz channel to a high 20 MHz channel.

80 MHz (4 types)

[XOOO], [OXOO], [OOXO], [OOOX]

160/80+80 MHz (12 types)

[XOOO OOOO], [OXOO OOOO], [OOXO OOOO], [OOOX OOOO],

[OOOO XOOO], [OOOO OXOO], [OOOO OOXO], [OOOO OOOX],

[XXOO OOOO], [OOXX OOOO], [OOOO XXOO], [OOOO OOXX]

240/160+80 MHz (9 types)

[XXOO OOOOOOOO], [OOXX OOOOOOOO], [OOOO XXOO OOOO],

[OOOO OOXX OOOO], [OOOO OOOOXXOO], [OOOO OOOO OOXX],

[XXXX OOOOOOOO], [OOOO XXXX OOOO], [OOOO OOOOXXXX]

320/160+160MHz (12 types)

[XXOO OOOOOOOOOOOO], [OOXX OOOOOOOOOOOO],

[OOOO XXOO OOOOOOOO], [OOOO OOXX OOOOOOOO],

[OOOO OOOOXXOO OOOO], [OOOO OOOOOOXX OOOO],

[OOOO OOOOOOOOXXOO], [OOOO OOOOOOOOOOXX],

[XXXX OOOOOOOOOOOO], [OOOO XXXX OOOOOOOO],

[OOOO OOOOXXXX OOOO], [OOOO OOOOOOOOXXXX]

In addition, the following puncturing pattern may be additionally applied to each bandwidth, and this will be referred to as an additional preamble puncturing pattern.

80 MHz (4 types)

[XOXO], [OXXO], [XOOX], [OXOX]

160/80+80 MHz (1 type)

[OOXX XXOO]

240/160+80 MHz (2 types)

[OOXX XXOO OOOO], [OOOO OOXX XXOO]

320/160+160 MHz (3 types)

[OOXX XXOO OOOOOOOO]

[OOOO OOXX XXOO OOOO],

[OOOO OOOOOOXX XXOO]

When only the basic preamble puncturing pattern is used as well as when an additional preamble puncturing pattern is used together, the preamble puncturing pattern field can consist of 4 bits, and the indicator can be set differently for each bandwidth as shown below. That is, the description of the bits of the Preamble puncturing pattern field may vary according to the information of the bandwidth field.

4.3.1 If Bandwidth Field is Example 1

When the bandwidth is 20 MHz or 40 MHz, preamble puncturing is not applied, so it does not matter what value the preamble puncturing pattern field is expressed in, but it may be set to 0 or 15 by default.

A case in which only the basic preamble puncturing pattern is used at 80 MHz is as follows.

0: non-preamble puncturing

1-4: Each value is mapped to 4 basic preamble puncturing patterns

5-15: reserved

A case in which an additional preamble puncturing pattern is also used at 80 MHz is as follows.

0: non-preamble puncturing

1 to 8: Each value is mapped to 4 basic preamble puncturing patterns and 4 additional preamble puncturing patterns

9-15: reserved

The case where only the basic preamble puncturing pattern is used in 160/80+80 MHz is as follows.

0: non-preamble puncturing

1 to 12: Each value is mapped to 12 basic preamble puncturing patterns

13-15: reserved

The case where an additional preamble puncturing pattern is also used in 160/80+80 MHz is as follows.

0: non-preamble puncturing

1 to 13: Each value is mapped to 12 basic preamble puncturing patterns and 1 additional preamble puncturing pattern

14-15: reserved

The case where only the basic preamble puncturing pattern is used in 240/160+80 MHz is as follows.

0: non-preamble puncturing

1~9: Each value is mapped to 9 basic preamble puncturing patterns

10-15: reserved

A case in which an additional preamble puncturing pattern is also used in 240/160+80 MHz is as follows.

0: non-preamble puncturing

1 to 11: Each value is mapped to 9 basic preamble puncturing patterns and 2 additional preamble puncturing patterns

12-15: reserved

A case in which only the basic preamble puncturing pattern is used in 320/160+160 MHz is as follows.

0: non-preamble puncturing

1 to 12: Each value is mapped to 12 basic preamble puncturing patterns

13-15: reserved

A case in which an additional preamble puncturing pattern is also used in 320/160+160 MHz is as follows.

0: non-preamble puncturing

1 to 15: Each value is mapped to 12 basic preamble puncturing patterns and 3 additional preamble puncturing patterns

4.3.2 When Bandwidth Field is Example 2

When the bandwidth is 20 MHz, 40 MHz and 80 MHz non-preamble puncturing mode, 160 MHz and 80+80 MHz non-preamble puncturing mode, 240 MHz and 160+80 MHz non-preamble puncturing mode, and 320 MHz and 160+160 MHz non-preamble puncturing mode, preamble puncturing is not applied, so it does not matter what value the Preamble puncturing pattern field is expressed in, but it may be set to 0 or 15 by default.

A case in which only the basic preamble puncturing pattern is used in the 80 MHz preamble puncturing mode is as follows.

0~3: Each value is mapped to 4 basic preamble puncturing patterns

4-15: reserved

A case in which an additional preamble puncturing pattern is also used in the 80 MHz preamble puncturing mode is as follows.

0-7: Each value is mapped to 4 basic preamble puncturing patterns and 4 additional preamble puncturing patterns

8-15: reserved

A case in which only the basic preamble puncturing pattern is used in the 160/80+80 MHz preamble puncturing mode is as follows.

0~11: Each value is mapped to 12 basic preamble puncturing patterns

12-15: reserved

A case in which an additional preamble puncturing pattern is also used in the 160/80+80 MHz preamble puncturing mode is as follows.

0-12: Each value is mapped to 12 basic preamble puncturing patterns and 1 additional preamble puncturing pattern

13-15: reserved

The case where only the basic preamble puncturing pattern is used in the 240/160+80 MHz preamble puncturing mode is as follows.

0~8: Each value is mapped to 9 basic preamble puncturing patterns

9-15: reserved

A case in which an additional preamble puncturing pattern is also used in the 240/160+80 MHz preamble puncturing mode is as follows.

0-10: Each value is mapped to 9 basic preamble puncturing patterns and 2 additional preamble puncturing patterns

11-15: reserved

A case in which only the basic preamble puncturing pattern is used in the 320/160+160 MHz preamble puncturing mode is as follows.

0~11: Each value is mapped to 12 basic preamble puncturing patterns

12-15: reserved

A case in which an additional preamble puncturing pattern is also used in the 320/160+160 MHz preamble puncturing mode is as follows.

0-14: Each value is mapped to 12 basic preamble puncturing patterns and 3 additional preamble puncturing patterns

15: reserved

From an overhead point of view, the method of 4.3.1 may be appropriate.

FIG. 26 is a procedure flowchart illustrating an operation of a transmission apparatus according to the present embodiment.

The example of FIG. 26 may be performed by a transmitting device (AP and/or non-AP STA). For example, the example of FIG. 26 may be performed by an AP transmitting an EHT SU PPDU, an EHT ER SU PPDU, or an EHT MU PPDU. The example of FIG. 26 may be performed by a non-AP that transmits an EHT SU PPDU, an EHT ER SU PPDU, and an EHT MU PPDU.

Some of each step (or detailed sub-step to be described later) of the example of FIG. 26 may be omitted or changed.

In step S2610, the transmitting device (ie, transmitting STA) may perform the channel access operation of paragraph 4.2 according to the above-described specification. For example, during the PIFS (this is just an example, it may be another IFS) just before the start of the TXOP (or just before the start of PPDU transmission), if the secondary 20 MHz, secondary 40 MHz, secondary 80 MHz, and secondary 160 MHz are idle, 320 MHz / 160+160 MHz mask PPDU can be transmitted, the BW (BandWidth) may be determined to be 320 MHz or 160 + 160 MHz through step S2610.

In step S2620, the transmitting STA may configure a PPDU. For example, the PPDU may be an EHT SU PPDU, an EHT ER SU PPDU, or an EHT MU PPDU. The PPDU may include an U-SIG as shown in FIG. 18 .

The transmitting STA may perform step S2620 based on the BW, determined in step S2610.

That is, as described above, specific (BW) n-bit (e.g., 4 bits) information may be included in the U-SIG or EHT-SIG, and the corresponding bit may be determined according to an example of 4.1. For example, the Bandwidth field of U-SIG or EHG-SIG may be configured based on the following elements.

0: 20 MHz

1: 40 MHz

2: 80 MHz non-preamble puncturing mode

3: 160 MHz and 80+80 MHz non-preamble puncturing mode

4: 240 MHz and 160+80 MHz non-preamble puncturing mode

5: 320 MHz and 160+160 MHz non-preamble puncturing mode

6: preamble puncturing in 80 MHz, where in the preamble only the secondary 20 MHz is punctured

7: preamble puncturing in 80 MHz, where in the preamble only one of the two 20 MHz subchannels in secondary 40 MHz is punctured

8: preamble puncturing in 160 MHz or 80+80 MHz, where in the primary 80 MHz of the preamble only the secondary 20 MHz is punctured

9: preamble puncturing in 160 MHz or 80+80 MHz, where in the primary 80 MHz of the preamble the primary 40 MHz is present, and at least one 20 MHz subchannel that is not in the primary 40 MHz is punctured

10: preamble puncturing in 240 MHz or 160+80 MHz, where in the primary 80 MHz of the preamble only the secondary 20 MHz is punctured

11: preamble puncturing in 240 MHz or 160+80 MHz, where in the primary 80 MHz of the preamble the primary 40 MHz is present, and at least one 20 MHz subchannel that is not in the primary 40 MHz is punctured

12: preamble puncturing in 320 MHz or 160+160 MHz, where in the primary 80 MHz of the preamble only the secondary 20 MHz is punctured

13: preamble puncturing in 320 MHz or 160+160 MHz, where in the primary 80 MHz of the preamble the primary 40 MHz is present, and at least one 20 MHz subchannel that is not in the primary 40 MHz is punctured

14~15: reserved

In step S2630, the transmitting device may transmit the PPDU configured in step S2620 to the receiving device based on step S2630.

While performing step S2630, the transmitting device may perform at least one of CSD, spatial mapping, IDFT/IFFT operation, GI insertion, and the like.

A signal/field/sequence constructed according to this specification may be transmitted in the form of FIG. 18 .

For example, the above-described U-SIG may be transmitted based on two OFDM symbols. For example, one OFDM symbol may include 26-bit information. The 26-bit information may include the above-described 4-bit BW information. Any m-bit information may be used instead of 26-bit information.

For 26-bit information, BCC encoding with ½ inefficiency may be applied. Interbiring by an interleaver may be applied to the BCC coded bits (ie, 52 bits). Constellation mapping by a constellation mapper may be performed on the interleaved 52 bits. Specifically, the BPSK module may be applied to generate 52 BPSK symbols. The 52 BSPK symbols may be matched to the remaining frequency domains (-28 to +28) except for DC tones and pilot tones (-21, -7, +7, +21) tones. Thereafter, it may be transmitted to the receiving STA through phase rotation, CSD, spatial mapping, IDFT/IFFT operation, and the like.

As shown in FIG. 1 , the transmitting apparatus (or transmitter) may include a memory 112, a processor 111, and a transceiver 113.

The memory 112 may store information on a plurality of Tone-Plan/RU that are described in the present specification.

The processor 111 may generate various RUs based on information stored in the memory 112 and configure a PPDU. An example of the PPDU generated by the processor 111 may be as shown in FIG. 18 .

The processor 111 may perform all/part of the operations illustrated in FIG. 26 .

The illustrated transceiver 113 includes an antenna and may perform analog signal processing. Specifically, the processor 111 may control the transceiver 113 to transmit the PPDU generated by the processor 111.

Alternatively, the processor 111 may generate a transmission PPDU and store information about the transmission PPDU in the memory 112.

FIG. 27 is a procedure flowchart illustrating an operation of a reception apparatus according to the present embodiment.

An example of FIG. 27 may be performed in the reception apparatus (AP and/or non-AP STA).

The example of FIG. 27 may be performed by a reception apparatus (AP and/or non-AP STA). For example, the example of FIG. 27 may be performed by a non-AP receiving an EHT SU PPDU, an EHT ER SU PPDU, or an EHT MU PPDU. The example of FIG. 27 may be performed by an AP that transmits an EHT SU PPDU, an EHT ER SU PPDU.

Some of each step (or detailed sub-step to be described later) of the example of FIG. 27 may be omitted.

In step S2710, the receiving device (receiving STA) may receive all or part of the PPDU through step S2710. The received signal may be in the form of FIG. 18 .

The sub-step of step S2710 may be determined based on step S2630 of FIG. 26 . That is, in step S2710, an operation for restoring the results of the CSD, spatial mapping, IDFT/IFFT operation, and GI insert operation applied in step S2630 may be performed.

In step S2720, the receiving STA may obtain information on the BW of the EHT PPDU by decoding information included in the U-SIG or EHT-SIG.

Through this, the receiving STA can complete decoding of other fields/symbols of the received PPDU.

As a result, the receiving STA may decode the data field included in the PPDU through step S2720. Thereafter, the receiving STA may perform a processing operation of transferring data decoded from the data field to a higher layer (e.g., MAC layer). In addition, when generation of a signal is instructed from the upper layer to the PHY layer in response to data transferred to the upper layer, a subsequent operation may be performed.

As shown in FIG. 1 , the reception apparatus may include a memory 112, a processor 111, and a transceiver 113.

The transceiver 123 may receive the PPDU based on the control of the processor 121. For example, the transceiver 123 may include a plurality of sub-units (not shown). For example, the transceiver 123 may include at least one receiving antenna and a filter for the corresponding receiving antenna.

The PPDU received through the transceiver 123 may be stored in the memory 122. The processor 121 may process decoding of the received PPDU through the memory 122. The processor 121 may obtain control information (e.g., EHT-SIG) regarding the Tone-Plan/RU included in the PPDU, and store the obtained control information in the memory 122.

The processor 121 may perform decoding on the received PPDU. Specifically, an operation for restoring the result of CSD, Spatial Mapping, IDFT/IFFT operation, and GI insert applied to the PPDU may be performed. CSD, Spatial Mapping, IDFT/IFFT operation, and operation of restoring the result of GI insert may be performed through a plurality of processing units (not shown) individually implemented in the processor 121.

In addition, the processor 121 may decode the data field of the PPDU received through the transceiver 123.

In addition, the processor 121 may process the decoded data. For example, the processor 121 may perform a processing operation of transferring information about the decoded data field to an upper layer (e.g., a MAC layer). In addition, when generation of a signal is instructed from the upper layer to the PHY layer in response to data transferred to the upper layer, a subsequent operation may be performed.

Hereinafter, the aforementioned embodiment is described with reference to FIGS. 1 to 27 .

FIG. 28 is a flowchart illustrating a procedure in which a transmitting STA transmits a PPDU according to the present embodiment.

An example of FIG. 28 may be performed in a network environment in which a next-generation wireless LAN system (e.g., IEEE 802.11be or EHT wireless LAN system) is supported. The next-generation wireless LAN system is a wireless LAN system improved from the 802.11ax system, and may satisfy backward compatibility with the 802.11ax system.

The example of FIG. 28 is performed by a transmitting STA, and the transmitting STA may correspond to an access point (AP). The receiving STA of FIG. 28 may correspond to an STA supporting an Extremely High Throughput (EHT) WLAN system.

This embodiment proposes a method and apparatus for indicating a preamble puncturing pattern of a broadband in OFDMA PPDU transmission.

In step S2810, the transmitting station (STA) generates a Physical Protocol Data Unit (PPDU).

In step S2820, the transmitting STA transmits the PPDU to the receiving STA through a broadband.

The PPDU includes a first signal field. The first signal field includes first information on a preamble puncturing pattern for each 80 MHz band in the broadband. The first information is set as a 4-bit bitmap for the each 80 MHz band. For example, when the broadband consists of three 80 MHz bands, the first information may be set as a 4-bit bitmap for the first 80 MHz band, a 4-bit bitmap for the second 80 MHz band, and/or a 4-bit bitmap for the third 80 MHz band.

The first signal field is a Universal-Signal (U-SIG) field. That is, this embodiment proposes a method of indicating (or signaling) a preamble puncturing pattern for each 80 MHz band based on a bitmap in the U-SIG field during OFDMA PPDU transmission. The U-SIG field may indicate a preamble puncturing pattern for each 80 MHz band for each 80 MHz band. Accordingly, information on the preamble puncturing pattern included in the U-SIG field may vary for each 80 MHz band.

The each 80 MHz band may include first to fourth 20 MHz channels. The first to fourth 20 MHz channels may be arranged in the order of low frequency to high frequency. That is, the first 20 MHz channel may be disposed at the lowest frequency, and the fourth 20 MHz channel may be disposed at the highest frequency.

Among the 4-bit bitmap, a first bit may include information on whether the first 20 MHz channel is punctured, a second bit may include information on whether the second 20 MHz channel is punctured, and a third bit may include information on whether the third 20 MHz channel is punctured, and a fourth bit may include information on whether the fourth 20 MHz channel is punctured.

The 4-bit bitmap may be set to one of 1111, 0111, 1011, 1101, 1110, 0011, 1100, and 1001. Here, 1 indicates that the corresponding 20 MHz channel is not punctured, and 0 indicates that the corresponding 20 MHz channel is punctured. For example, when the 4-bit bitmap is set to 1001, it can be seen that the first and fourth 20 MHz channels are not punctured, and the second and third 20 MHz channels are punctured.

The PPDU further includes a second signal field. The second signal field may be an Extremely High Throughput-Signal (EHT-SIG) field. The second signal field may include first signal information duplicated for the first and third 20 MHz channels and second signal information duplicated for the second and fourth 20 MHz channels (The EHT-SIG field may have a 1 2 1 2 structure). That is, information included in the second signal field for the first and third 20 MHz channels may be the same as the first signal information, and information included in the second signal field for the second and fourth 20 MHz channels may be the same as the second signal information. Accordingly, the receiving STA may also know the first signal information for the third 20 MHz channel by decoding the first signal information for the first 20 MHz channel, and the second signal information for the fourth 20 MHz channel by decoding the second signal information for the second 20 MHz channel.

The structure of the second signal field may be set based on first information on the preamble puncturing pattern included in the first signal field. For example, when the 4-bit bitmap is set to 0111, the first 20 MHz channel may be punctured. Since the first 20 MHz channel is punctured, the second signal field may not include the first signal information for the first 20 MHz channel. Accordingly, the second signal field may include the first signal information for the third 20 MHz channel and the second signal information for the second and fourth 20 MHz channels.

The first signal field may include second information on the bandwidth of the broadband. The second information may consist of 3 bits. The bandwidth of the broadband is determined as one of 20 MHz, 40 MHz, 80 MHz, 160/80+80 MHz, 240/160+80 MHz, and 320/160+160 MHz based on the 3 bits. For example, when the 3 bits are 000, the bandwidth of the broadband is 20 MHz. When the 3 bits are 001, the bandwidth of the broadband is 40 MHz. When the 3 bits are 010, the bandwidth of the broadband is 80 MHz. When the 3 bits are 011, the bandwidth of the broadband is 160/80+80 MHz. When the 3 bits are 100, the bandwidth of the broadband is 240/160+80 MHz. When the 3 bits are 101, the bandwidth of the broadband is 320 /160+160 MHz. And the 3 bits which are 110 or 111 may be set as a reserved bit. Alternatively, it may not be indicated when the bandwidth is 240/160+80 MHz based on the 3 bits (indicated when the bandwidth is 320/160+160 MHz or 80 MHz puncturing).

When the bandwidth of the broadband is 320/160+160 MHz, the broadband includes first to fourth 80 MHz channels. The preamble puncturing pattern for the first 80 MHz channel may be determined based on the 4-bit bitmap for the first 80 MHz channel. The preamble puncturing pattern for the second 80 MHz channel may be determined based on the 4-bit bitmap for the second 80 MHz channel. The preamble puncturing pattern for the third 80 MHz channel may be determined based on the 4-bit bitmap for the third 80 MHz channel. The preamble puncturing pattern for the fourth 80 MHz channel may be determined based on the 4-bit bitmap for the fourth 80 MHz channel. That is, each of the preamble puncturing patterns for the first to fourth 80 MHz channels may be signaled as a 4-bit bitmap. The preamble puncturing pattern may be a pattern in which puncturing is performed in units of 20 MHz in a channel except for a primary 20 MHz channel.

The PPDU may further include a data field. The data field may be received through a resource unit determined based on the first and second signal fields.

The U-SIG may include a version independent field and a version dependent field.

The PPDU includes a control field and a data field. The control field includes a first control field supporting a legacy wireless LAN system and a second control field supporting an 802.11be wireless LAN system. The second control field may include the U-SIG field or the EHT-SIG field. The second control field may include allocation information for an RU to which the data field is to be transmitted.

FIG. 29 is a flowchart illustrating a procedure for a receiving STA to receive a PPDU according to the present embodiment.

An example of FIG. 29 may be performed in a network environment in which a next-generation wireless LAN system (e.g., IEEE 802.11be or EHT wireless LAN system) is supported. The next-generation wireless LAN system is a wireless LAN system improved from the 802.11ax system, and may satisfy backward compatibility with the 802.11ax system.

The example of FIG. 29 is performed by a receiving STA, and the receiving STA may correspond to an STA supporting an Extremely High Throughput (EHT) WLAN system. The transmitting STA of FIG. 29 may correspond to an access point (AP).

This embodiment proposes a method and apparatus for indicating a preamble puncturing pattern of a broadband in OFDMA PPDU transmission.

In step S2910, the receiving station (STA) receives a Physical Protocol Data Unit (PPDU) through a broadband from a transmitting STA.

In step S2920, the receiving STA decodes the PPDU.

The PPDU includes a first signal field. The first signal field includes first information on a preamble puncturing pattern for each 80 MHz band in the broadband. The first information is set as a 4-bit bitmap for the each 80 MHz band. For example, when the broadband consists of three 80 MHz bands, the first information may be set as a 4-bit bitmap for the first 80 MHz band, a 4-bit bitmap for the second 80 MHz band, and/or a 4-bit bitmap for the third 80 MHz band.

The first signal field is a Universal-Signal (U-SIG) field. That is, this embodiment proposes a method of indicating (or signaling) a preamble puncturing pattern for each 80 MHz band based on a bitmap in the U-SIG field during OFDMA PPDU transmission. The U-SIG field may indicate a preamble puncturing pattern for each 80 MHz band for each 80 MHz band. Accordingly, information on the preamble puncturing pattern included in the U-SIG field may vary for each 80 MHz band.

The each 80 MHz band may include first to fourth 20 MHz channels. The first to fourth 20 MHz channels may be arranged in the order of low frequency to high frequency. That is, the first 20 MHz channel may be disposed at the lowest frequency, and the fourth 20 MHz channel may be disposed at the highest frequency.

Among the 4-bit bitmap, a first bit may include information on whether the first 20 MHz channel is punctured, a second bit may include information on whether the second 20 MHz channel is punctured, and a third bit may include information on whether the third 20 MHz channel is punctured, and a fourth bit may include information on whether the fourth 20 MHz channel is punctured.

The 4-bit bitmap may be set to one of 1111, 0111, 1011, 1101, 1110, 0011, 1100, and 1001. Here, 1 indicates that the corresponding 20 MHz channel is not punctured, and 0 indicates that the corresponding 20 MHz channel is punctured. For example, when the 4-bit bitmap is set to 1001, it can be seen that the first and fourth 20 MHz channels are not punctured, and the second and third 20 MHz channels are punctured.

The PPDU further includes a second signal field. The second signal field may be an Extremely High Throughput-Signal (EHT-SIG) field. The second signal field may include first signal information duplicated for the first and third 20 MHz channels and second signal information duplicated for the second and fourth 20 MHz channels (The EHT-SIG field may have a 1 2 1 2 structure). That is, information included in the second signal field for the first and third 20 MHz channels may be the same as the first signal information, and information included in the second signal field for the second and fourth 20 MHz channels may be the same as the second signal information. Accordingly, the receiving STA may also know the first signal information for the third 20 MHz channel by decoding the first signal information for the first 20 MHz channel, and the second signal information for the fourth 20 MHz channel by decoding the second signal information for the second 20 MHz channel.

The structure of the second signal field may be set based on first information on the preamble puncturing pattern included in the first signal field. For example, when the 4-bit bitmap is set to 0111, the first 20 MHz channel may be punctured. Since the first 20 MHz channel is punctured, the second signal field may not include the first signal information for the first 20 MHz channel. Accordingly, the second signal field may include the first signal information for the third 20 MHz channel and the second signal information for the second and fourth 20 MHz channels.

The first signal field may include second information on the bandwidth of the broadband. The second information may consist of 3 bits. The bandwidth of the broadband is determined as one of 20 MHz, 40 MHz, 80 MHz, 160/80+80 MHz, 240/160+80 MHz, and 320/160+160 MHz based on the 3 bits. For example, when the 3 bits are 000, the bandwidth of the broadband is 20 MHz. When the 3 bits are 001, the bandwidth of the broadband is 40 MHz. When the 3 bits are 010, the bandwidth of the broadband is 80 MHz. When the 3 bits are 011, the bandwidth of the broadband is 160/80+80 MHz. When the 3 bits are 100, the bandwidth of the broadband is 240/160+80 MHz. When the 3 bits are 101, the bandwidth of the broadband is 320 /160+160 MHz. And the 3 bits which are 110 or 111 may be set as a reserved bit. Alternatively, it may not be indicated when the bandwidth is 240/160+80 MHz based on the 3 bits (indicated when the bandwidth is 320/160+160 MHz or 80 MHz puncturing).

When the bandwidth of the broadband is 320/160+160 MHz, the broadband includes first to fourth 80 MHz channels. The preamble puncturing pattern for the first 80 MHz channel may be determined based on the 4-bit bitmap for the first 80 MHz channel. The preamble puncturing pattern for the second 80 MHz channel may be determined based on the 4-bit bitmap for the second 80 MHz channel. The preamble puncturing pattern for the third 80 MHz channel may be determined based on the 4-bit bitmap for the third 80 MHz channel. The preamble puncturing pattern for the fourth 80 MHz channel may be determined based on the 4-bit bitmap for the fourth 80 MHz channel. That is, each of the preamble puncturing patterns for the first to fourth 80 MHz channels may be signaled as a 4-bit bitmap. The preamble puncturing pattern may be a pattern in which puncturing is performed in units of 20 MHz in a channel except for a primary 20 MHz channel.

The PPDU may further include a data field. The data field may be received through a resource unit determined based on the first and second signal fields.

The U-SIG may include a version independent field and a version dependent field.

The PPDU includes a control field and a data field. The control field includes a first control field supporting a legacy wireless LAN system and a second control field supporting an 802.11be wireless LAN system. The second control field may include the U-SIG field or the EHT-SIG field. The second control field may include allocation information for an RU to which the data field is to be transmitted.

5. Apparatus/Device Configuration

The technical features of the present specification described above may be applied to various devices and methods. For example, the above-described technical features of the present specification may be performed/supported through the apparatus of FIGS. 1 and/or 19 . For example, the technical features of the present specification described above may be applied only to a part of FIGS. 1 and/or 19 . For example, the technical features of the present specification described above are implemented based on the processing chip(s) 114 and 124 of FIG. 1 , or implemented based on the processor(s) 111 and 121 and the memory(s) 112 and 122 of FIG. 1 , or may be implemented based on the processor 610 and the memory 620 of FIG. 19 . For example, the apparatus of the present specification may receive a Physical Protocol Data Unit (PPDU) through a broadband from a transmitting STA; and decodes the PPDU.

The technical features of the present specification may be implemented based on a computer readable medium (CRM). For example, the CRM proposed by the present specification is at least one computer readable medium including at least one computer readable medium including instructions based on being executed by at least one processor.

The CRM may store instructions perform operations comprising: receiving a Physical Protocol Data Unit (PPDU) through a broadband from a transmitting STA; and decoding the PPDU. The instructions stored in the CRM of the present specification may be executed by at least one processor. At least one processor related to CRM in the present specification may be the processor(s) 111 and 121 or the processing chip(s) 114 and 124 of FIG. 1 , or the processor 610 of FIG. 19 . Meanwhile, the CRM of the present specification may be the memory(s) 112 and 122 of FIG. 1 , the memory 620 of FIG. 19 , or a separate external memory/storage medium/disk.

The foregoing technical features of this specification are applicable to various applications or business models. For example, the foregoing technical features may be applied for wireless communication of a device supporting artificial intelligence (AI).

Artificial intelligence refers to a field of study on artificial intelligence or methodologies for creating artificial intelligence, and machine learning refers to a field of study on methodologies for defining and solving various issues in the area of artificial intelligence. Machine learning is also defined as an algorithm for improving the performance of an operation through steady experiences of the operation.

An artificial neural network (ANN) is a model used in machine learning and may refer to an overall problem-solving model that includes artificial neurons (nodes) forming a network by combining synapses. The artificial neural network may be defined by a pattern of connection between neurons of different layers, a learning process of updating a model parameter, and an activation function generating an output value.

The artificial neural network may include an input layer, an output layer, and optionally one or more hidden layers. Each layer includes one or more neurons, and the artificial neural network may include synapses that connect neurons. In the artificial neural network, each neuron may output a function value of an activation function of input signals input through a synapse, weights, and deviations.

A model parameter refers to a parameter determined through learning and includes a weight of synapse connection and a deviation of a neuron. A hyper-parameter refers to a parameter to be set before learning in a machine learning algorithm and includes a learning rate, the number of iterations, a mini-batch size, and an initialization function.

Learning an artificial neural network may be intended to determine a model parameter for minimizing a loss function. The loss function may be used as an index for determining an optimal model parameter in a process of learning the artificial neural network.

Machine learning may be classified into supervised learning, unsupervised learning, and reinforcement learning.

Supervised learning refers to a method of training an artificial neural network with a label given for training data, wherein the label may indicate a correct answer (or result value) that the artificial neural network needs to infer when the training data is input to the artificial neural network. Unsupervised learning may refer to a method of training an artificial neural network without a label given for training data. Reinforcement learning may refer to a training method for training an agent defined in an environment to choose an action or a sequence of actions to maximize a cumulative reward in each state.

Machine learning implemented with a deep neural network (DNN) including a plurality of hidden layers among artificial neural networks is referred to as deep learning, and deep learning is part of machine learning. Hereinafter, machine learning is construed as including deep learning.

The foregoing technical features may be applied to wireless communication of a robot.

Robots may refer to machinery that automatically process or operate a given task with own ability thereof. In particular, a robot having a function of recognizing an environment and autonomously making a judgment to perform an operation may be referred to as an intelligent robot.

Robots may be classified into industrial, medical, household, military robots and the like according uses or fields. A robot may include an actuator or a driver including a motor to perform various physical operations, such as moving a robot j oint. In addition, a movable robot may include a wheel, a brake, a propeller, and the like in a driver to run on the ground or fly in the air through the driver.

The foregoing technical features may be applied to a device supporting extended reality.

Extended reality collectively refers to virtual reality (VR), augmented reality (AR), and mixed reality (MR). VR technology is a computer graphic technology of providing a real-world object and background only in a CG image, AR technology is a computer graphic technology of providing a virtual CG image on a real object image, and MR technology is a computer graphic technology of providing virtual objects mixed and combined with the real world.

MR technology is similar to AR technology in that a real object and a virtual object are displayed together. However, a virtual object is used as a supplement to a real object in AR technology, whereas a virtual object and a real object are used as equal statuses in MR technology.

XR technology may be applied to a head-mount display (HMD), a head-up display (HUD), a mobile phone, a tablet PC, a laptop computer, a desktop computer, a TV, digital signage, and the like. A device to which XR technology is applied may be referred to as an XR device.

The claims recited in the present specification may be combined in a variety of ways. For example, the technical features of the method claims of the present specification may be combined to be implemented as a device, and the technical features of the device claims of the present specification may be combined to be implemented by a method. In addition, the technical characteristics of the method claim of the present specification and the technical characteristics of the device claim may be combined to be implemented as a device, and the technical characteristics of the method claim of the present specification and the technical characteristics of the device claim may be combined to be implemented by a method. 

1. A method in a wireless Local Area Network (LAN) system, the method comprising: receiving, by a receiving station (STA), a Physical Protocol Data Unit (PPDU) through a broadband from a transmitting STA; and decoding, by the receiving STA, the PPDU, wherein the PPDU is received based on an Orthogonal Frequency Division Multiple Access (OFDMA) scheme, wherein the PPDU includes a first signal field, wherein the first signal field includes first information on a preamble puncturing pattern for each 80 MHz band in the broadband, and wherein the first information is set as a 4-bit bitmap for each 80 MHz band.
 2. The method of claim 1, wherein the each 80 MHz band includes first to fourth 20 MHz channels, wherein the first to fourth 20 MHz channels are arranged in the order of low frequency to high frequency, Among the 4-bit bitmap, a first bit includes information on whether the first 20 MHz channel is punctured, a second bit includes information on whether the second 20 MHz channel is punctured, and a third bit includes information on whether the third 20 MHz channel is punctured, and a fourth bit includes information on whether the fourth 20 MHz channel is punctured.
 3. The method of claim 2, wherein the 4-bit bitmap is set to one of 1111, 0111, 1011, 1101, 1110, 0011, 1100, and
 1001. 4. The method of claim 3, wherein the PPDU further includes a second signal field, wherein the second signal field includes first signal information duplicated for the first and third 20 MHz channels and second signal information duplicated for the second and fourth 20 MHz channels.
 5. The method of claim 4, wherein when the 4-bit bitmap is set to 0111, the first 20 MHz channel is punctured, wherein the second signal field includes the first signal information for the third 20 MHz channel and the second signal information for the second and fourth 20 MHz channels.
 6. The method of claim 4, wherein the first signal field is a Universal-Signal (U-SIG) field, wherein the second signal field is an Extremely High Throughput-Signal (EHT-SIG) field, wherein the PPDU further includes a data field, wherein the data field is received through a resource unit determined based on the first and second signal fields.
 7. The method of claim 1, wherein the first signal field includes second information on the bandwidth of the broadband, wherein the second information consists of 3 bits, wherein the bandwidth of the broadband is determined as one of 20 MHz, 40 MHz, 80 MHz, 160/80+80 MHz, 240/160+80 MHz, and 320/160+160 MHz based on the 3 bits.
 8. The method of claim 7, wherein when the bandwidth of the broadband is 320/160+160 MHz, the broadband includes first to fourth 80 MHz channels, wherein the preamble puncturing pattern for the first 80 MHz channel is determined based on the 4-bit bitmap for the first 80 MHz channel, wherein the preamble puncturing pattern for the second 80 MHz channel is determined based on the 4-bit bitmap for the second 80 MHz channel, wherein the preamble puncturing pattern for the third 80 MHz channel is determined based on the 4-bit bitmap for the third 80 MHz channel, wherein the preamble puncturing pattern for the fourth 80 MHz channel is determined based on the 4-bit bitmap for the fourth 80 MHz channel.
 9. The method of claim 1, wherein the preamble puncturing pattern is a pattern in which puncturing is performed in units of 20 MHz in a channel except for a primary 20 MHz channel.
 10. A receiving station (STA) in a wireless Local Area Network (LAN), the receiving STA comprising: a memory; a transceiver; and a processor operatively coupled to the memory and the transceiver, wherein the processor is configured to: receive a Physical Protocol Data Unit (PPDU) through a broadband from a transmitting STA; and decode the PPDU, wherein the PPDU is received based on an Orthogonal Frequency Division Multiple Access (OFDMA) scheme, wherein the PPDU includes a first signal field, wherein the first signal field includes first information on a preamble puncturing pattern for each 80 MHz band in the broadband, and wherein the first information is set as a 4-bit bitmap for each 80 MHz band.
 11. A method in a wireless Local Area Network (LAN), the method comprising: generating, by a transmitting station (STA), a Physical Protocol Data Unit (PPDU); and transmitting, by the transmitting STA, the PPDU through a broadband to a receiving STA, wherein the PPDU is received based on an Orthogonal Frequency Division Multiple Access (OFDMA) scheme, wherein the PPDU includes a first signal field, wherein the first signal field includes first information on a preamble puncturing pattern for each 80 MHz band in the broadband, and wherein the first information is set as a 4-bit bitmap for each 80 MHz band.
 12. The method of claim 11, wherein the each 80 MHz band includes first to fourth 20 MHz channels, wherein the first to fourth 20 MHz channels are arranged in the order of low frequency to high frequency, Among the 4-bit bitmap, a first bit includes information on whether the first 20 MHz channel is punctured, a second bit includes information on whether the second 20 MHz channel is punctured, and a third bit includes information on whether the third 20 MHz channel is punctured, and a fourth bit includes information on whether the fourth 20 MHz channel is punctured.
 13. The method of claim 12, wherein the 4-bit bitmap is set to one of 1111, 0111, 1011, 1101, 1110, 0011, 1100, and
 1001. 14. The method of claim 13, wherein the PPDU further includes a second signal field, wherein the second signal field includes first signal information duplicated for the first and third 20 MHz channels and second signal information duplicated for the second and fourth 20 MHz channels.
 15. The method of claim 14, wherein when the 4-bit bitmap is set to 0111, the first 20 MHz channel is punctured, wherein the second signal field includes the first signal information for the third 20 MHz channel and the second signal information for the second and fourth 20 MHz channels. 16-20. (canceled) 